Journal of Operations Management 20 (2002) 747–767 From supply to demand chain management: efficiency and customer satisfaction Jussi Heikkilä∗ Helsinki University of Technology, P.O. Box 9555, FIN-02015 Hut, Finland Abstract How do companies in the fast-growing industries achieve good customer satisfaction together with efficiency in supply chain management (SCM)? This inductive case study of six customer cases of Nokia Networks, one of the leading providers of mobile telecommunication technology, led to propositions exploring that question. Good relationship between the customer and the supplier contributes to reliable information flows, and reliable demand information flows in turn contribute to high efficiency—these are well-researched issues also in other industry environments. But in a fast-growing systems business such as mobile telecommunications industry, the supplier needs to be able to adapt its offering to a wide variety of customer situations and needs. Understanding the customer’s situation and need together with the right offering contributes to good co-operation in improving the joint demand chain, which further leads to superior demand chain efficiency and high customer satisfaction. © 2002 Elsevier Science B.V. All rights reserved. Keywords: Marketing/operations interface; Logistics/distribution; Time-based competition; Case study research 1. Introduction One of the main challenges of today’s manufacturing is to be both efficient and contribute to high effectiveness, i.e. customer satisfaction. Information is increasingly available through e-business, customer relationship management (CRM) and supply chain management (SCM) solutions, making it—at least in theory—possible to serve customers individually with customized bundles of goods and services. However, going too far in customization would ruin efficiency. On the other hand, too rigid an approach to SCM would risk customer satisfaction. How to find a good balance between good customer satisfaction and supply chain efficiency? Our answer is to start from understanding the situation and need in distinct customer segments—which is not ∗ Tel.: +358-50-376-1090; fax: +358-9-451-3665. E-mail address: jussi.heikkila@hut.fi (J. Heikkilä). normally the starting point for operations managers to begin their improvement efforts. The next step is to develop manageable number of alternative modular service offerings to be adapted to individual customer situations and needs. The final step is to take the relationship characteristics into consideration and develop a joint improvement agenda together with the customer to develop optimum operative efficiency within the constraints set by the objectives important for the customer; and if the joint improvement agenda is implemented in good co-operation, high customer satisfaction will follow. Nokia Networks, one of the leading technology vendors for mobile telecommunications networks, has recently experienced all this. The background of this paper is a business situation in which Nokia Networks implemented a demand chain efficiency improvement project with several of their customers. The company delivers equipment for their customers’ mobile cellular telecommunications networks. The cellular network 0272-6963/02/$ – see front matter © 2002 Elsevier Science B.V. All rights reserved. PII: S 0 2 7 2 - 6 9 6 3 ( 0 2 ) 0 0 0 3 8 - 4 748 J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 consists of switches, base station controllers and base transceiver stations (BTS) (more commonly known as base stations). Base stations are delivered in thousands to a telecommunications operator’s network. There are some hundreds of telecommunications operators as customers for all technology vendors globally. Nokia Networks implemented a demand chain improvement program called Handshake with several customers. The central elements of the Handshake program were funnel forecasting with the expectation that the customer could systematically improve its planning accuracy over time, removing inventories between the base station manufacturing plant and the customer’s network building operation, and assembling the final base station configurations in the plant for direct delivery to final destinations. The global supply chain performance targets set by Nokia Networks in 1997 (in relative terms for confidentiality reasons) are given in Table 1. The results of the efficiency improvement projects initiated by Nokia were mixed: success in some of them and failure in others. The following quotes illustrate the difference in customers’ reactions to Nokia’s proposed Handshake program. A successful Alpha case as described by Alpha’s Section Manager responsible for their network building with Nokia: The initial reaction for Nokia’s proposal was a great surprise. Nokia had always been very strict about the fixed 4 months lead-time for units. We were like hit by a log when (Nokia’s new Head of Logistics) came and said that the lead-time could be shortened from 4 months to 10 days and configurations defined only in the call-off. The flexibility has grown considerably. Earlier we were suffering from lack of material and had to live with that. Now the problem has disappeared. Removal of our warehouse has also been a big achievement. The right material is directly moved to the right destination, there are no more problems of having wrong materials in warehouses. On the other hand, we have to do more work in forecasting and planning the configurations. A less successful Beta case as described by Nokia’s Quality and Processes Manager for Beta: In our first discussion with Beta Contract Manager concerning the Handshake project he felt that we were just trying to save our own costs by taking down the country warehouse. He asked how much price reduction would he get? . . . When Nokia started piloting the Handshake project with Beta, the lead-time was reduced from 9 to 4 weeks. Several meetings were organized to explain the new model and the advantages that it would give to Beta, and also to get Beta’s acceptance to the model. Nokia’s country organization and Beta set up joint development work-groups. The work-groups visited both companies, and they met monthly for 1.5 years. However, it took months before the work-groups started really working. . . . Beta did not change its practice of ordering. They demanded immediate reduction of lead-time without starting forecasting. Handshake was a perfect fit for some of the customers, whereas in other cases there was a serious misfit between the support that the customer needed from their supplier partner and the improvement program elements. The resultant question for Nokia was how to tailor their demand chain improvement program according to the distinct needs and characteristics of specific customer segments. The demand chain architecture must be robust—in order to apply different demand chains in different customer situations. 1.1. Objective, research question and unit of analysis Table 1 Nokia Networks’ global supply chain performance improvement targets set in 1997 (in relative terms) Targets 1997 Reduction in 1998 (%) Reduction in 1999 (%) Inventory reduction Order fulfillment lead-time Non-perfect order fulfillment 100 100 16 79 34 82 100 33 64 The objective of our research was to increase understanding of factors contributing to well-performing demand chains in the mobile cellular networks industry. The aim was through case study research to find new perspectives for the demand chain structure and for the industrial customer–supplier relationships, and how they influence the demand chain performance in a young, fast-growing industry. The research question was as follows: J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 What is the architecture of a well-performing demand chain in a young, fast-growing industry, selling systems with varying hardware and software content to industrial customers? The main research question was further divided into questions of information and material flows, customer–supplier relationships, and demand chain performance. The unit of analysis was a demand chain for building cellular networks, consisting of a customer (telecommunications operator), the technology supplier’s organizational units responsible for serving the customer in network building, and the factory assembling and delivering base stations to the customer’s network. 1.2. Supply/demand chain management The SCM concept extends the view of operations from a single business unit or a company to the whole supply chain. Essentially, SCM is a set of practices aimed at managing and co-ordinating the supply chain from raw material suppliers to the ultimate customer. The objective of SCM is to improve the entire process rather than focusing on local optimization of particular business units. A number of researchers suggest that better performance can be achieved by consolidating customer and supplier bases, removing unnecessary steps in the chain, speeding up information and material flows, and creating long-term partnerships with major customers and suppliers to leverage the capabilities of several companies in the chain. Previous management theory in the area of SCM can be broadly divided into two main categories. The first category is studies of primarily the chain structure (e.g. Forrester, 1958, 1961; Burbidge, 1961; Sharman, 1984; Sterman, 1989; Towill et al., 1992; Lee and Billington, 1992; Lee et al., 1997a,b; Holmström, 1994, 1995; Fisher, 1997). The second group is primarily about industrial networks and the relationships between organizations in the chain (e.g. Williamson, 1985; Heide and John, 1990; Mohr and Spekman, 1994; Hakansson and Snehota, 1995; Kumar et al., 1995; Dyer, 1996a,b,c, 1997; Monczka et al., 1998). Some scholars suggest using the term demand chain management instead of SCM (Vollmann et al., 1995, 1997, 2000; Vollmann and Cordon, 1998). This puts 749 emphasis on the needs of the marketplace and designing the chain to satisfy these needs, instead of starting with the supplier/manufacturer and working forward. In this research, the emphasis on the customer needs is adopted as the starting point for supply/demand chain management. 1.3. Mobile cellular networks demand chain The mobile telecommunications industry in 1990s was a fast-growing global industry. New technologies were constantly developed for cellular networks and liberalized markets were growing at rates over 50% annually during the latter half of the 1990s. The traditional division of companies in the demand chain—telecommunications operators, suppliers of telecommunications equipment and systems, and suppliers of components and modules—changed radically. Deregulation of telecommunications markets forced operators to focus sharply on competitive end-user services by increasing the variety of services. New operators transferred parts of operators’ traditional activities to technology suppliers, such as network planning and building, and even operation of telecommunications networks. At the same time, the suppliers were also moving up in the value chain. Specialized contract manufacturers developed increasing capability of offering manufacturing services to allow telecommunications technology vendors—among them Alcatel, Ericsson, Lucent, Motorola, Nokia, Nortel, and Siemens—to concentrate on meeting the changing needs of the telecommunications operators. Throughout the 1990s, the leading companies providing technology for the cellular networks industry enjoyed strong growth and good profitability. Companies offering new technologies entered a large number of fast-growing new markets all over the world. New supply chains were quickly built to serve a wide variety of customers. Building a cellular network engages the customer and the supplier in a business relationship that lasts for several years. The cellular network consists of switches, base station controllers and BTS. The standardization of the technology is not completely open. It is possible to combine switches of one supplier to base station subsystems (base station controller+BTS) from another supplier, but it is not possible to mix BTSs from several vendors within one base station 750 J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 subsystem. This means high switching costs when changing from one supplier to another in a geographic area. However, it happens that the technology vendor is changed during the several years of building and expanding a mobile telecommunications network, meaning replacement of the old vendor’s technology with that of the new one. In our research, we concentrated on the demand chain of BTSs, the most numerous network element in a cellular network. The process of building a BTS site starts from network planning. Network planning gives the approximate locations of the BTS sites as a basis for site acquisition and/or provides a list of the sites readily available. Further, network planning defines how sites will be connected and related to the base station controllers. Site acquisition locates three alternative sites for further technical review. One is selected, resulting in negotiations for a lease agreement with the site owner and applying for necessary permits to build the BTS site. When the lease agreement is signed and the necessary permits granted, construction works would start to build the necessary foundations, antenna masts and power supplies. After the construction work is finished, the site is ready for installation of the BTS, antennas and other auxiliary equipment. Either a line in a fixed network or a radio link connects the site to base station controller. Finally, the BTS is integrated operatively into the network. Many of the steps in the BTS site building and installation process have high uncertainty. It is not always sure that the owner of a site will agree to lease it. It is also uncertain if all the necessary permits will be granted for a site, or, even if the permits are granted, there are questions as to when. Construction and installation times also raise uncertainty. If the network is built using leased lines from the owner of the fixed network, receiving the leased lines can also be delayed. For these reasons, network building can be iterative in nature. Configuration of an individual site depends on the neighboring sites. If, for some reason, a planned site cannot be used, it can influence the configuration of other sites around it. The above described complexity, combined with very rapid and unpredictable growth in the demand for mobile communication services makes effective SCM a challenging task for both the customer and the supplier. Success in network building requires close co-operation between the two parties at several stages of the building process. The supplier needs to be ready to take on varying roles to deal with the customer depending on the customer’s objectives, own resources, skills and capabilities. 2. Literature review 2.1. Supply/demand chain structure Time-based management and the relationship between speed of operations and efficiency has been one of the key issues in operations management literature during the 1980s and 1990s (e.g. Stalk, 1988; Stalk and Holt, 1990; Womack et al., 1991; The Toyota Production System, 1995). Stalk (1988) describes how time has become one of the most important sources of competitive advantage in manufacturing industries. He describes the background for “Japan’s secret weapon” (Womack et al., 1991) or “lean thinking” (Womack and Jones, 1996) by illustrating how the competitive advantage of Japanese manufacturing industry evolved from low labor costs—through scale-based strategy, focused factory and flexible manufacturing—to time-based competitive advantage. Stalk describes companies as systems and says that competitive advantage can be achieved by breaking the “debilitating loop strangling traditional manufacturing planning”. This means that traditional manufacturing requires long lead-times to resolve conflicts between various jobs or activities that require the same resources. The long lead-times require sales forecasts to guide planning. Long lead-times make the accuracy of sales forecasts decline. Forecasting errors increase inventories and the need for safety stocks at all levels. Errors in forecasts mean more unscheduled jobs in the production line, increasing the lead-times for the scheduled jobs. The planning loop expands, drives up costs, increases delays, and creates system inefficiencies. Holmström (1994, 1995) has empirically studied the efficiency potential of speed in operations. His main results are empirical indications of a strong positive correlation between speed and efficiency in manufacturing and that a focus on speed of operations helps expose and remove self-induced sources of uncertainty. He claims that the main contributor to uncertainty in slow operations is distorted communication in the activity system. Based on his findings of J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 a “speed threshold” he suggests that inventory commitment needs to be reduced to a point where demand distortion is diminished and a synchronization of production with demand is possible in order to improve performance by speeding up operations. One of the main system issues in supply chains is industrial dynamics and management of the bullwhip (or Forrester or whiplash or whipsaw) effect. This refers to the phenomenon where orders to the supplier tend to have larger variance than sales to the buying organization (i.e. demand distortion), and the distortion propagates upstream in an amplified form (i.e. variance amplification). This phenomenon is related to the information flows among the members in the supply chain. Information flows in terms of orders have a direct impact on the production scheduling, inventory control and delivery plans of individual members in the supply chain. Information-feedback systems owe their behavior to three characteristics—structure, delays and amplification (Forrester, 1961; Sterman, 1989). The structure of a system tells how the parts are related to one another. Delays exist in the availability of information, in making decisions based on the information, and in taking action on the decisions. Amplification usually exists throughout systems and it is observed when an action is more forceful than might seem to be implied by the information inputs to the system. Lee et al. (1997b) claim that the bullwhip effect is an outcome of the strategic interactions among rational supply chain members who are optimizing. They suggest the following sources of the bullwhip effect: demand signal processing, rationing game, order batching and price variations. In the existence of any of these four sources, bullwhip is caused by rational behavior of the members in the chain. Lack of inter-company communication combined with large time lags between receipt and transmittal of information are at the root of the problem (Metters, 1997). Consequently, solutions to the problem often involve increasing the abilities of companies to co-ordinate activity and cut lead-times. Uncertainty and the nature of the forecasting problem have a considerable impact on the supply chain structure. According to Fisher (1997), the first step in devising an effective supply chain is to consider the nature of the demand for the products. If products are classified on the basis of their demand patterns, 751 they fall into one of two categories: primarily functional or primarily innovative. Each category requires a distinctly different kind of supply chain. Fisher argues that with their high profit margins and volatile demand, innovative products require a fundamentally different supply chain than stable, low-margin functional products. Two distinct types of functions performed by a supply chain should be recognized: a physical function and a market mediation function. A supply chain’s physical function is readily apparent and includes converting raw materials into parts, components, and eventually finished goods, and transporting all of them from one point in the supply chain to the next. Less visible but equally important is market mediation (demand knowledge), the purpose of which is to ensure that the variety of products reaching the marketplace matches what consumers need. Most important in the environment for innovative products is reading market signals correctly and being able to react quickly during the product’s short life cycle. The crucial flow of information occurs from the marketplace to the chain. The critical decisions about capacity and inventory are not about minimizing costs but where in the chain to position inventory and available production capacity in order to hedge against uncertain demand. Suppliers should be chosen for their speed and flexibility, not for their low cost (Fisher, 1997). The first step in designing a responsive supply chain is to accept that uncertainty is inherent in innovative products. Uncertainty can be avoided by cutting lead-times and increasing the supply chain’s flexibility so that it can produce to order or at least assemble the product at a time closer to when demand materializes and can be accurately forecast. The company can hedge against the remaining uncertainty with buffers of inventory or excess capacity (Fisher, 1997). Many recent texts emphasize that the product, manufacturing process and supply chain structure need to be considered together to create a capability for mass customization (Pine et al., 1993; Lampel and Minzberg, 1996; Feitzinger and Lee, 1997; Fine, 1998; Duray et al., 2000). Different industries require different approaches for customization. The BTS configuration and delivery belongs to “menu industries” in the categorization of Lampel and Minzberg (1996). In a menu industry, buyers have a menu of choices from which to select features of the final product. 752 J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 Customized standardization tends to be the preferred customization strategy in this type of industry. Transactions between the buyer and the supplier involve negotiations and reciprocal relationships between buyers and sellers. Once the configuration has been decided, the production function assembles prefabricated components into finished products. 2.2. Industrial customer–supplier relationships Texts on supply chain structure typically suggest that great benefits could be achieved by co-operation between the customer and the supplier and giving the supplier access to the customer’s real demand data. However, as Lee et al. (1997b) state, a different problem is under what conditions the customer would be willing to co-operate with the supplier, to give access to real demand data and to co-ordinate its ordering policies for the benefit of the supplier. Economists have recognized that ‘resource owners increase productivity through co-operative specialization’ (Dyer, 1997; further Alchian and Demsetz, 1972). Indeed, the supply chains are characterized by inter-firm specialization such that individual firms engage in a narrow range of activities that are embedded in a complex chain of input–output relations with other firms. Productivity gains in the supply chains are possible when firms are willing to make transaction or relation-specific investments (Williamson, 1985; Perry, 1989). Recent empirical work confirms that investments in relation-specific assets are often correlated with better performance compared to more arms-length relationships (Parkhe, 1993; Dyer, 1996a). Recent SCM and relationship marketing research has attempted to increase understanding of the conditions for win–win partnerships, i.e. customer–supplier relationships in which close long-term co-operation simultaneously increases the value produced by the demand chain and decreases the overall cost of the chain. Several researchers have come to the conclusion that companies need to divide their customer–supplier relationships into classes along the continuum from ‘arms-length’ relationships to true partnerships (Moody, 1993; Vollmann et al., 1995; Lambert et al., 1996; Cooper et al., 1997; Friis Olsen and Ellram, 1997; Bensaou, 1999). While true strategic partnerships create new value, they are costly to develop, nurture and maintain. Also, they are risky given the specialized investments they require (Cooper et al., 1997; Bensaou, 1999). The number of real partnerships a company can build and maintain is limited. Therefore, partnership type of relationships cannot be expected to be built with a large number of customers or suppliers, and focusing the resources on building the right relationships requires careful planning and decision-making. Commitment refers to the willingness of buyers and suppliers to exert effort on behalf of the relationship. Commitment to a relationship is most frequently demonstrated by committing resources to the relationship, which may occur in the form of an organization’s time, money, facilities, etc. These types of resources are often referred to as ‘asset-specific’ resources, in that they are directed specifically towards the other party (Dyer, 1997). Several other studies have also found a relationship between resource commitment and the joint action or continuity between parties within inter-organizational relationships (Heide and John, 1990; Yoshino and Rangan, 1995). These results suggest that successful partnerships result when both buyers and suppliers demonstrate a willingness to commit a variety of assets to a set of future transactions. Two aspects of communication behavior that address the extent to which the information exchanged is effective in a partnership include information sharing, and the level of information quality and participation (Monczka et al., 1998). Both of these aspects of information sharing (quantity and quality) are required to successfully develop supplier partnerships. Information sharing refers to the extent to which critical and proprietary information is communicated to one’s supply chain partner (Mohr and Spekman, 1994). Suppliers and customers can form joint development teams to improve various aspects in the supply chain or suppliers can suggest changes that may lead to quality or cost improvements (Clark, 1989). Information quality includes such aspects as the accuracy, timeliness, adequacy, and credibility of information exchanged (Huber and Daft, 1987). Information participation refers to the extent to which partners engage jointly in planning and goal setting (Mohr and Spekman, 1994). These information attributes are closely related and critical in enabling members of a partnership to co-ordinate their activities. The earlier J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 mentioned works suggest that successful supplier alliances are associated with high levels of information sharing and information quality and participation. Interdependence exists when one actor does not entirely control all of the conditions necessary for achievement of an action or a desired outcome. Resource dependence has been explored in empirical studies, which investigate the relationship between dependence and control in buyer–supplier relationships (Handfield, 1993). For instance, dealers are less opportunistic when they depend on a primary supplier, whereas suppliers with control over dealer’s decisions exhibit greater opportunism (Provan and Skinner, 1989). Resource dependence can also influence supplier just-in-time (JIT) delivery performance (Handfield, 1993). The above literature suggests that successful partnerships are expected to be characterized by higher levels of interdependence. Trust encompasses two essential elements (Kumar et al., 1995): (1) trust in the partner’s reliability, that is the belief that the partner stands by its word, fulfills promised role obligations, and is sincere, and (2) trust in the partner’s benevolence, that is the belief that the partner is interested in the firm’s welfare and will not take unexpected actions that will negatively affect the firm. Trust, therefore, exists when a firm believes its partner is reliable and benevolent. Conflict is behavior that impedes, blocks, or frustrates another firm’s goal pursuit (Kumar et al., 1995). Perceived conflict is the magnitude of present conflict acknowledged and perceived by the firm. 3. Research method and data collection Theory building from inductive case research was chosen as an appropriate research approach for this study. The objective is increased understanding of the phenomenon. The research is directed toward development of testable hypotheses that are generalizable in various application environments. This research approach is a suitable method to describe and explore new phenomena (Handfield and Melnyk, 1998; Eisenhardt, 1989) or to build new operations management theories (Meredith, 1998). This type of theory building relies on direct observations of the objects or participants in the theory and its development (Glaser and Strauss, 1967; Yin, 1989). The research approach 753 is inductive, and utilizes both qualitative and quantitative data. The case study allows the investigation to retain the holistic and meaningful characteristic of complex real life events (Yin, 1989). Research constructs direct attention to what should be studied in order to answer the research questions (Yin, 1989). In this research, there are three main constructs to be operationalized: information and material flows together forming the structure in a demand chain, the relationship between an industrial customer and the supplier, and the performance of a demand chain. Operationalization of these research constructs is shown in Table 2. 3.1. Case selection and data collection Six supply chains of Nokia Networks were studied with a different customer in each case in a different European country. These six cases were selected using the following criteria: • The first two cases (customers Alpha and Beta, the names used here to identify the firms are pseudonyms) represented two extremes in supply chain performance in Nokia. The higher performing supply chain (Alpha) represented an industrial customer–supplier relationship in which the two organizations had co-operated for a relatively long time, the two organizations had jointly carried out a Handshake supply chain improvement project successfully, and the supply chain performance was considered good by Nokia’s managers. The lower-performing case (Beta) represented a relationship in which the two organizations had co-operated for a few years and implementing SCM improvement was perceived as difficult. • Another high performing (Delta) and another low performing (Theta) case were selected for study after the first two cases were analyzed. The objective was to either reinforce or reject patterns emerging from the first two cases related to success or failure in supply chain relationships. • The two other cases (Gamma and Epsilon) that were selected after the analysis of the first two cases represented relationships that were just recently established and the customers’ cellular network was not yet fully opened for traffic. Right from the beginning of the relationship, Nokia was trying to implement 754 J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 Table 2 Operationalization of the research constructs: data collection protocol for each of the issues Issues in the research constructs Data collection protocol Demand chain structure Members of the demand chain Information and material flows (delays) between the members Process description from the interviews The database of order-to-delivery cycles Sources of delays and distortions in the information flows Demand signaling Forecasting practice from the interviews Rationing game Forecasting accuracy from the forecasting data and interviews Order batching Frequency of ordering from the interviews Customer–supplier relationship Commitment to future interaction Duration of the relationship from the interviews Communication Amount of information sharing, information quality Participation Communication patterns from the interviews Trust Reliability, benevolence and perceived conflict from the survey Demand chain performance Customer satisfaction (effectiveness) Efficiency Information sharing (both quantity and quality of information) from the survey Customer respondents’ perception of the support received from the supplier to achieve customer’s demand chain management objectives—from the survey Delivery lead-times from the database of order-to-delivery cycles Inventory commitment in terms of days-of-supply from the database of order-to-delivery cycles and from the interviews. Share of order changes from the database of order-to-delivery cycles and from the interviews the same lean SCM practices (such as funnel forecasting, low inventories and assemble-to-order deliveries of BTSs) as in the Handshake improvement projects with the customers in the other cases. In one (Epsilon) of these two new customer relationships, Nokia delivered a full turnkey cellular network to the customer. Theory-building research typically combines multiple data collection methods. This triangulation provides stronger substantiation of constructs and hypotheses (Jick, 1979). Combination of data types should be highly synergistic. Quantitative evidence can indicate relationships, which may not be salient from pure qualitative data. Qualitative data is useful for understanding the rationale of the underlying relationships. In our research, data collection consisted of the following three parts in each of the six cases: • Quantitative data was collected of the information and material flows and supply chain performance. (forecasting and delivery data of the BTS volumes, a database of 605 order-to-delivery cycles, inventory commitment in all the supply chains, data of order changes in all the six cases). • Interviewing the supplier and customer representatives provided qualitative data of the customer–supplier relationship (35 informants, out of which 27 were representatives of Nokia country organizations and eight represented the customers). • Based on the results of the qualitative interviews, a survey questionnaire was developed and sent to respondents in the customer and supplier organizations in order to collect quantified perceptions of the relationship and co-operation in the network building process (46 responses received for 63 questionnaires mailed, 73% response rate). 3.2. Data analysis Data collection, data analysis and theory building were closely linked in this research, and together formed an iterative process. The research process started by definition of the research questions and J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 755 756 J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 selection of initial research constructs based on the preliminary practical and theoretical understanding of the phenomenon studied. There were three levels of analysis in each of the data analysis steps of the research process: • within-case analysis; • cross-case analysis; • expert analysis: presentation and discussion of the results with the research project steering group consisting of industry experts and research advisors. Within-case analysis of each case involved detailed case study write-ups for each case. These write-ups were descriptions structured according to the constructs used in the data collection. They were central in the generation of the insight into each case, because they helped to cope with the analysis process of the large volume of data (Eisenhardt, 1989). The written case descriptions were essential for the reliability of the research. They also enabled the informants to review the case analysis of each case, thereby improving the construct validity. This process allowed the unique patterns of each case to emerge before generalized patterns across the cases were created. The three types of data collected—quantitative data, interview responses and survey results—were combined in the case study write-ups. All three types of data were used as important sources of evidence when developing an understanding of demand chain management in each case; no single type of data was allowed to dominate. Descriptive statistical measures (arithmetic mean, S.D., and skew) were calculated for interpretation of survey results and quantitative data. Because of the research approach used and the relatively small sample sizes this was considered as an appropriate way to analyze the quantitative data. The second level in the case analysis was the search for cross-case patterns. In the analysis of the first two cases this meant looking at the potential reasons for differences in the supply chain performance. This helped to sharpen the research constructs and to focus the data collection in the further steps of the research. Cross-case analysis of all the six cases started by analyzing the three types of relationships that were originally used in selecting the cases (successful, non-successful and new demand chains). Within-group similarities were sought first coupled with inter-group differences. The second method used was to compare the cases across the initial groups. Overall, the idea behind the cross-case searching method was to force the investigation to go beyond initial impressions (Eisenhardt, 1989). Also, cross-case searching tactics enhance the probability to capture the novel findings that may exist in the data. 4. How to combine efficiency and customer satisfaction? The cross-case analysis results are organized according to the background of the customer–supplier relationship in the cases studied (Table 3), and according to the three main research constructs used to guide the research: demand chain structure (Table 4), customer–supplier relationship (Table 5), and demand chain performance (Table 6). Refer to Table 3 for the comparison of the cases in terms of the background of the relationships. For further illustration, Nokia’s Project Implementation Manager for Epsilon and Country Logistics Manager for Gamma described the planning challenge in a new demand chain relationship as follows: Logistics is a big mess in these projects. The approach is too theoretical, not practical enough. Logistics is causing our problems. Putting a complete site package together is in principle a good idea, as suggested in the Handshake model. However, it does not work. In the planning there is 70–80% reliability for the following week, but there is no understanding of the needs for 3 weeks out. Use of site packages is possible in an established project in which the required competencies, systems and planning processes are in place. In a new project, it is better to start with a big warehouse (that can deliver materials fast). The following conclusions are made to explain how the background of the customer–supplier relationships might be related to the demand chain efficiency in the cellular network building: Competence of the customer, duration of the relationship between the customer and the supplier and experience of the employees working on the customer–supplier relationship increase demand chain efficiency (this proposition is based on the finding nos. 1–3, see Table 3). J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 757 758 J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 Table 5 Relationship characteristics Communication and trust Alpha Delta Epsilon Gamma Beta Communication patterns Frequent communication forums established on all levels and in all functions between the two organizations Theta Finding number 13 Information sharing Nokia respondents Customer respondents 4.97 5.01 4.43 5.01 3.76 4.75 5.09 4.89 4.78 4.66 4.63 14 Reliability Nokia respondents Customer respondents 4.91 5.68 5.16 4.88 3.96 2.60 3.90 3.27 4.38 3.85 4.10 Benevolence Nokia respondents Customer respondents 4.20 5.60 4.12 5.00 3.32 3.40 3.80 3.93 3.93 4.70 4.20 Perceived conflict Nokia respondents Customer respondents 1.75 1.90 2.30 2.90 5.10 3.50 2.63 4.00 3.25 3.13 4.33 15 16 17 The numbers given are arithmetic means of responses from the indicated respondent group. The scale was a 7-point Likert scale with 7 representing high and 1 representing low information sharing, reliability, benevolence, and conflict in the relationship with the other party. The importance of efficiency as a demand chain management objective increases when the network building stage matures and the growth of the network stabilizes. Demand chain efficiency grows because of the increased attention to it (finding nos. 4 and 5). The research data on the demand chain structure in the six cases are given in Table 4. The following conclusions are made to explain how the demand chain structure might be related to the demand chain efficiency in the cellular network building: Lower demand chain efficiency is related to multi-step forecasting process and consistent over-forecasting from the customer to the supplier’s country organization and from the supplier’s country organization to the factory (finding no. 6). Lower demand chain efficiency is related to changing orders, order batching or delay in the ordering information (finding no. 7). The waiting time of a delivery in the target country (customer-specific inventory) is a major part of the total inventory commitment in the chain and is related to the overall efficiency of the demand chains. Removal of a customer-specific inventory is a “speed threshold” that allows radical improvement of supply chain performance (finding no. 10). The research data on the characteristics of the customer–supplier relationships in the six cases is shown in Table 5. In addition to the survey results in the table, the following quotes from the interview informants in the high-performance Alpha case and the lower-performing Gamma case indicate considerable difference in how trust was perceived in the customer–supplier relationships: There is a spirit of co-operation between Alpha and Nokia. Both organizations are willing to do extra work for the partner in order to help them forward. The contract between the two organizations defines prices, but otherwise it is not followed in every detail. An example is failure reports. Alpha wants to have monthly Nokia’s failure reports for the network. This is more often than the contract defines, but we are not going to charge any extra for this service. (Nokia Product Manager for Alpha). Current relationship with Nokia country organization is improving. Our biggest issue is that we do not feel they are open and honest with us. They J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 759 760 J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 continue to tell what we want to hear and deliver the bad news at the 23rd hour. This impacts our planning. . . . We feel they need to improve the management of their subcontractors and the flow of materials. . . . Their different organizational units have conflicting goals, for example site implementation versus logistics. (Gamma Network Planning and Implementation Manager). The following conclusions are made to explain how the customer–supplier relationship might influence the demand chain efficiency in the cellular network building: Good demand chain efficiency is related to good trust between the customer and the supplier, i.e. high reliability and benevolence and low conflict in the customer–supplier relationship (this proposition is based on finding nos. 15–17 in Table 5). High quantity of information sharing is a necessary but not always sufficient condition for good quality of information sharing and high demand chain efficiency (finding nos. 13 and 14). Low perceived reliability of the supplier is interpreted as low quality of information sharing. Lower quality of information sharing in the relationship is related to lower demand chain efficiency (finding no. 15). The research data on the demand chain performance is given in Table 6. The following conclusions are suggested to explain how the various demand chain performance issues are related in the cellular network building: High demand chain efficiency is not sufficient to explain the overall customer satisfaction in the cellular network building. For example, technology and its perceived quality might contribute more to the overall customer satisfaction than demand chain efficiency (finding nos. 21–23). Radical demand chain improvement requires good co-operation from the customer. The customer’s clear perceived gain from co-operation is related to good success in demand chain improvement (removing customer’s central warehouse is a sufficient incentive for the customer to co-operate in radical improvement; incremental reduction of the supplier’s demand chain cost is not) (finding nos. 24 and 25). 4.1. Cross-case analysis results according to effectiveness and efficiency The cross-case analysis results are summarized in Fig. 1. Each of the six cases is positioned in a matrix according to the demand chain effectiveness (i.e. the match between the customer need and the demand chain structure) and the demand chain efficiency (i.e. the total inventory commitment from BTS assembly start until integration to the telecommunications network). The direct BTS delivery Handshake model implemented in the Alpha and Delta cases matched well with the customers’ situation and need, making the demand chain structure effective. The following reasons contributed to the successful implementation of the direct delivery Handshake model: • There was an established relationship between the customers and Nokia. The customers had good competence of working in their industry and market. Organizations and communication mechanisms were well established. • The network building was in an advanced stage, with stabilized growth, focusing on optimizing the network and building new end-customer features in the network. • High information sharing and trust made it possible to work together to improve the demand chain performance. High gain perceived by the customer of the demand chain improvement project increased the motivation of the customers to co-operate. • The customers had good planning capabilities and they took responsibility for the planning information provided by them. • Because of the good co-operation it was possible to remove the customer-specific inventory, resulting in major demand chain efficiency improvement and good customer satisfaction. Comparison of cases in the same effectiveness group results in explanations for efficiency differences between cases. Delta has longer total lead-time, higher inventory commitment and more order changes than Alpha, even if they operate with the same demand J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 761 Fig. 1. Summary of the cross-case analysis. chain structure in a comparable customer situation and relationship. Similar findings are made when comparing the Epsilon, Gamma and Beta cases. Epsilon demand chain has higher efficiency than the other two demand chains because there is no gaming in the forecasts, there are no delays and no batching in the ordering process. Beta has lowest efficiency of these three cases. It also has the highest consistent bias in forecasting and longest delays in the ordering process. For this type of customer, a highly reactive chain is the only possibility, as also demanded by Beta’s Contract and Negotiations Manager: Theta forms a special case among the cases studied. In principle, the country warehouse model with BTS modules in the warehouse would be an effective model to support fast network building with high flexibility. However, having all elements of low efficiency in place ruined the effectiveness of the model. There was gaming in forecasts, long delays in the ordering process and monthly batches in ordering, resulting in very high total inventory commitment, total lead-time and share of order changes. Flexibility of deliveries is the most important factor influencing the performance of our chain, followed by on-time delivery and quality. Flexibility means having the possibility to make changes in the content of the delivery if needed during the agreed lead-time. Sometimes a shorter than agreed lead-time is needed. . . . Lead-time could be reduced if BTS configuration could be made in our country. International transportation takes too long time. Site acquisition and preparation make the site process uncertain. 5. Toward a model of demand chain management This case research of the six customer relationships in cellular network building indicates that there are a variety of customer relationships that the supplier needs to adapt to. Therefore, the crucial question for a supplier is how to design the demand chain architecture according to the needs and characteristics of distinct customer needs and situations. Demand chain architecture means understanding the nature of demand and developing a modular 762 J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 demand chain structure—including decisions of the order-penetration point, inventory buffer locations and sizes, and assembly capacity. The above described research results are next positioned to the existing theoretical literature of demand chain management. Stalk (1988) suggests demand chain efficiency can be improved by reducing the time delays in the flow of information and materials throughout the chain. Holmström (1995) suggests that inventory commitment needs to be reduced to a point where demand distortion is diminished and synchronization of production with demand is possible in order to improve performance by speeding up operations. There is no reason to disagree with these overall objectives to improve demand chain efficiency. But the research findings indicate that reduction of inventory commitment might be challenging with a large number of customers even if it brings radical improvements with some. Inventory reduction and an effort to speed-up operations can fail with non-co-operative customers, and result in lowered trust in the relationship, and further in distorted demand information and lowered efficiency. The research findings comply with those of Forrester (1958, 1961) and Sterman (1989) showing that the basic structure of a demand chain and delays and distortions in the information flows cause inefficiencies in the chain. Also, the findings support the results of Lee et al. (1997b) that demand signaling, rationing game and order batching are sources of distorted information flows and result in chain inefficiencies. The research findings on the customer–supplier relationship comply with the results of Heide and John (1990) and Mohr and Spekman (1994) that the historical length of the relationship increases the continuity expectations, which in turn increase the level of co-operation (joint action); and that co-operation in terms of co-ordination, participation, and joint problem solving (also Monczka et al., 1998) are good predictors for the success of a partnership. Dyer (1997) also sees continuity as an important factor for a successful partnership, through repeated transactions with a small set of suppliers. The research results are also consistent with the earlier research in finding high trust between the partners being related to good demand chain efficiency. Mohr and Spekman (1994), Dyer (1997), and Monczka et al. (1998) all found trust an important factor contributing to partnership success. There is a difference between the results of some of the earlier research and our findings in the information sharing between customer and supplier in industrial relationships. Dyer (1997) found that extensive inter-firm information sharing reduces asymmetric information and results in lower transaction costs. Monczka et al. (1998) found that bilateral communication behavior played a significant role in determining partnership success. No major differences could be observed in this research in the quantity of information sharing between high and low efficiency relationships. It seems that information sharing is perceived as open in all customer–supplier relationships in cellular network building, as far as it can be concluded by studying six relationships of one supplier in the industry. However, there were differences in how the supplier’s reliability was perceived. Reliability was perceived as higher in the high efficiency relationships than in the low efficiency relationships. A conclusion is drawn here that even if the quantity of information sharing might be a necessary precondition for well-performing supply chain relationships, it is not always sufficient. Information sharing quality comes into focus, particularly in an industry with a large number of new companies, new markets, new employees, and new relationships. Cellular network systems clearly fall in the category of “innovative products” in the typology of Fisher (1997). The highly uncertain receptiveness of the market increases the risk of shortages or excess supplies. The cost of shortages is that the customer loses sales in an emerging (sometimes exponentially growing) market. The high number of final product configurations increases the risk of obsolescence and the cost of excess supplies. According to Fisher (1997), the most important factor when designing global delivery chains is to understand the behavior of demand in a particular industry and organize the chain to serve it accordingly. In such an environment, the crucial flow of information occurs from the marketplace to the chain. It is important to cut lead-times to produce the product close to the time when demand materializes. The critical decisions about inventory and capacity are where in the chain to position inventory and available production and assembly capacity in order to have maximum flexibility to deal with the highly fluctuating demand. J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 Fisher suggests that selection of demand chain structure primarily depends on the industry characteristics. We feel that this is too simple an approach. Based on the findings of this study, it is suggested that several different chains are needed within a single industry to meet various customer needs and situations. This oversimplification by Fisher makes us suggest that strategic SCM needs to be well integrated with the market segmentation ideas in marketing. In operations management, Hill (1994) has earlier talked about this integration in the context of manufacturing strategy. Companies require a strategy not based solely on marketing, manufacturing, logistics, or any other function, but one that embraces the interface between markets and functions. The link between functional strategies comes from the markets the business serves. SCM must choose its processes and design its infrastructure in ways that help a company’s bundles of goods and services to win orders, and that choice and design must be adaptable to changing business needs. Thus, the company as a whole needs to agree on the markets and segments within these markets in which it decides to compete. In no way can these critical decisions be the responsibility of a single function. As a function, marketing will have an important and essential (but not the only) view. An essential perspective of a firm’s markets has to come from operations. This perspective is established by determining the order-qualifiers and order-winners that operations needs to provide (compare to Hill, 1994). Order-qualifiers are the criteria that a firm must meet for a customer to even consider it as a possible supplier. Order-winners are those criteria that win the orders. In the cellular network building—as in most other project businesses as well—order-qualifiers are related to the customer’s perception of the supplier’s capability to fulfill the contract requirements. Order-winners for new relationships in this type of high-technology industry are probably often related to technological matters. But essential order-winners for continuous business are developed during the co-operation between the customer and the supplier when building the network. For a new operator striving for launching their services to market, and thereafter aggressively competing for the market share with the established telecommunications operators, speed and support from an experienced technology vendor are above all other criteria. 763 Efficiency that is perceived to slow down the network building and expansion is not acceptable. Established operators in an advanced stage of network optimization are more willing to appreciate the cost advantage of a lean supply chain. The technology vendor needs to understand the differing customer needs and situations, implement best demand chain structure in co-operation with the customer, and through improved customer satisfaction contribute to better relationship and co-operation. The research findings are summarized in the demand chain management model presented in Fig. 2. The model consists of the following five propositions, emerging from the research of the six cases in the mobile telecommunication industry: Proposition 1. Good relationship characteristics contribute to reliable information flows. Proposition 2. Reliable information flows contribute to high efficiency. Proposition 3. Understanding the customer situation and need and good relationship characteristics contribute to co-operation between the customer and supplier. Proposition 4. Good co-operation in implementing demand chain improvement contributes to high efficiency and high customer satisfaction. Proposition 5. High customer satisfaction contributes to good relationship characteristics. The first two propositions state the already wellknown relationships in industrial supply chains that good customer–supplier relationships contribute to reliable information flows, that in turn result in high supply chain efficiency. However, this well-known equation needs stratification for fast-growing system businesses, where the high growth results in a large number of different types of customers with different situations and needs. A technology vendor that wants to achieve overall good customer satisfaction, needs to understand the individual customers’ needs and objectives and to be able to support the customer in meeting their objectives. Good understanding of the customer needs builds a good basis for fruitful co-operation 764 J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 Fig. 2. The model of demand chain management. between the customer and the supplier, increasing the demand chain efficiency and customer satisfaction. following priority order of decision-making criteria was proposed to design alternative modular demand chain processes: 6. Managerial implications 1. Supporting the customer’s network building process by sufficiently fast deliveries. 2. Building a product structure to enable decisions on the order-penetration point for a base station according to the customer need. The main argument resulting from this research is that several demand chain structures are necessary to adapt to varying customer needs and situations. The Fig. 3. The three alternative demand chain structures suggested to serve different customers in the mobile network business. J. Heikkilä / Journal of Operations Management 20 (2002) 747–767 3. Flexibility in the assembly capacity to meet the market uncertainty. 4. Inventory optimization within the constraints resulting from the above criteria. Three demand chain processes as variations of generic demand chain architecture were proposed to serve the different customer needs of Nokia Networks in the cellular networks industry (Fig. 3). An important aspect was to see the alternative processes as modular, supporting a consistent move of particular customer–supplier relationships from one demand chain process to a more advanced one when the relationship characteristics allow. Increased rate of returns in implementing demand chain management was experienced at Nokia when the positive feedback of good customer satisfaction feeding into the relationship characteristics started taking effect (Proposition 5 in the model, see also Sterman, 2000; Senge and Sterman, 1994; Senge, 1990 for modeling organizational learning). The original Handshake model of Nokia Networks was developed into a new program called breakthrough inventory rotation days (BIRD). The BIRD program aimed at improving customer satisfaction and implementing efficient demand chains for a large number of Nokia Networks’ customers. By the end of the year 2000, during 1.5 years of the BIRD program implementation, about 40% average reduction in inventory levels was reached despite of substantial growth in sales. BIRD focused on Nokia Networks’ European customers. The new processes were implemented for customer projects in 17 different European countries by the end of year 2000 (Tissari and Heikkilä, 2001). 7. Conclusions Companies in the fast-growing industries need to be constantly developing their supply chain efficiency. At the same time, they are all the time facing a variety of new customers, with new situations and needs. Our study of six customer cases of Nokia Networks explored how to combine high supply chain efficiency with good customer satisfaction. We propose that supply chain improvement should start from the customer end, and the concept of SCM should be changed into demand chain management. 765 Demand chain management understands the need for good customer–supplier relationships and reliable information flows as contributors to high efficiency. But in a fast-growing systems business such as mobile telecommunications industry, the supplier also needs to be able to adapt its offering to a wide variety of customers. Understanding the customer’s need together with the right demand chain structure results in good co-operation in improving the joint demand chain, which further leads to superior demand chain efficiency and customer satisfaction. The current article addresses the process of demand chain improvement in the fast-growing, high-technology environment of the mobile telecommunications industry. 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