The Directors of ‘Smoothtools Ltd’ are considering the introduction of Lean Manufacturing to the
plant but have number of queries about the concepts involved. As a result, they have requested that
you write a short report which clearly explains the following:
Question 1
What is the difference between ‘push’, ‘pull’ and ‘Theory of constraints’ approaches to planning
and control? Explain using diagrams, highlighting the pros and cons of each.
Push Approach
The process of production in a push system is driven by forecast with a key focus on maximizing
efficiency at every step. The production of goods within the system are based on the anticipated
demands of the customers (Powell et al., 2013). The risk of excessive inventory and
overproduction according to (Apreutesei et al., 2010) happens to be one of the main drawbacks of
the push approach. The push approach is commonly used in mass production or within a factory
setting that uses Material or Enterprise Resource Planning (MRP/ERP). The push approach is
based on just in case (JIC) thinking.
Pros

Demands are quickly made as products are made already.

Economies of scale are created as the system gave room for bulk production.
Cons

Overestimated demands can trigger the risk of overproduction and excessive inventory.

High cost of inventory due to the storage of goods produced.
Diagram
Figure 1 Make to Stock Process Signals based on demand schedule (Apreutesei et al., 2010)
Pull Approach
The pull approach in contrast operates based on the actual demands of the customers. Goods are
only produced upon an order from the customer. This is to ensure that production of goods are
initiated only when they are needed (Powell et al., 2013). This helps the company in reducing
inventory levels and as well minimizing waste. The pull approach is based on just in time (JIT)
thinking.
Pros

Minimizes risk of overproduction.

Reduces inventory costs as goods are produced as needed.
Cons

May not be able to meet sudden spikes in demand.

Production lead time can delay delivery to the customer.
Diagram
Figure 2 Make to order process based on customer demand (Apreutesei et al., 2010)
Theory of Constraints Approach
The Theory of Constraints (TOC) is an organizational method of change that focuses around profit
improvement. The main concept of TOC is that for every organization, there must be at least a
single constraint. Constraint according to (Pacheco et al., 2019) is any limiting factor that hinders
the organization from achieving its goal or getting more of whatever, they set out for which in
most cases is profit. TOC has been identified as the main balance between the push and pull
approach. The main focus of TOC is identifying and alleviating bottlenecks within the process of
production. It also gives more emphasis in the optimization of the whole system rather than the
individual components. The primary aim of TOC is to enhance the entire efficiency of the system
and this is achieved by addressing the constraints systematically (Dekier, 2012).
Pros

Focuses on improving the bottleneck, increasing overall efficiency.

Balances inventory levels and response times.
Cons

Requires continuous adjustment and monitoring.

May not be suitable for all types of businesses.
Diagram (Pacheco et al., 2019)
Approach
Pros
Cons
Push
Economies of scale, Quick response to Risk
demand
Pull
Minimizes
Improves
overproduction,
High
inventory costs
overproduction,
inventory costs
TOC
of
efficiency,
inventory and response
Low May
not
meet
sudden
demand,
Production lead time
Balances Requires continuous adjustment, May
not suit all businesses
Question 2
What is ‘level scheduling’? and what might be the pre-requisites before we can introduce it?
Level scheduling
Level scheduling which is also referred to as the Heijunka is a technique or method in lean
manufacturing used in reducing production unevenness and ensuring a more predictable and
consistent workflow (Wahab et al., 2013). This method or technique involves the leveling out the
types of products and volume within a given timeframe in order to meet-up with the demands of
the customers without creating any excessive inventory or overburdening the manufacturing
system.
Pre-requisites for level scheduling
There are a number of pre-requisites that must be met before implementing level scheduling so as
to ensure its success (Christopher & Towill, 2001; Wahab et al., 2013).
1. Stable Production Process: The process of production should be predictable and stable,
with minimal disruptions and variations.
2. Flexible Equipment and Workforce: It is essential to have the ability of quickly
switching between the various types of products or the ability of adjusting product
volumes.
3. Accurate Demand Forecasting: It is necessary and vital to have a reliable forecast of the
demands of the customers in order to plan an effective production schedule.
4. Pull-based Production System: with a pull-based system such as the kanban, level
scheduling performs the best where production of goods is driven by real customer demand
rather than bear forecast.
5. Standardized Work: to ensure consistency in production timing and quality, the processes
should be standardized.
6. Continuous Improvement Culture: there should be a culture within the organization that
supports continuous improvement such as the Kaizen for adapting and refining the level
scheduling system.
Diagram of Level Scheduling
A simple table illustrating what level scheduling might look like
Time Period
Product A
Product B
Product C
Week 1
100
65
80
Week 2
100
65
80
Week 3
100
65
80
Week 4
100
65
80
In this table, production is leveled across four weeks, ensuring that each product is produced in the
same quantity each week, smoothing out the production process.
Benefits of Level Scheduling (Tomaszewska, 2023)

Reduced Inventory: level of inventory is kept to a minimum through aligning production
closely with demand.

Improved Flow: smoother production flow always results in shorter lead times and
immediate response to the demands of the customers.

Reduced Production Stress: level scheduling helps in balancing organizational resources
which in turn, minimizes the chances of overstressing machineries or the workforce.

Increased Flexibility: The system adapts easily to sudden change in customer demands
and responses.
Implementing and adopting level scheduling in a production environment can be a tasking and
complex process. However, using the right and appropriate re-requisites, the process can easily
result in a significant improvement in responsiveness and efficiency.
Question 3
Will the ‘Autocratic’ culture of the company fit with the philosophy of ‘Lean’? What is the ‘Lean
Philosophy’ in relation to people ? and what ‘working practices’ need to be put in place in order
to move to a Lean environment?
Autocratic culture and lean philosophy
The philosophy of lean and the autocratic culture of an organization may not necessarily
accommodate each other as (Leite & Vieira, 2015) concluded. (González et al., 2015) emphasizes
that the lean philosophy is all about employee’s empowerment, waste elimination, and continuous
improvement. This can however conflict with the style of autocratic culture where employees have
little autonomy due to a centralized decision-making system.
Lean Philosophy in Relation to People
In relation to people, the Lean philosophy is all about empowering employees and creating a
culture of continuous improvement. It emphasizes the following;

Respect for People: employees based on lean philosophy are believed to be thew most
important resources of any organization (Leite & Vieira, 2015). Employees knowledge and
skills are encouraged and respected in this philosophy. It further promotes employee
involvement in decision-making process and problem solving.

Continuous Improvement (Kaizen): a culture where all employees are involved in
decision-making, contributing to small-incremental improvement to services, products or
processes on a regular basis is promoted through lean philosophy (Chiarini et al., 2018).

Elimination of Waste (Muda): all forms of waste are eliminated in lean philosophy such
as wasted resources, time, and talent (Leah Gourley, 2020). Employees are constantly
encouraged and reminded to identify and eliminate any form of activity that bears no value
to production of goods and services.
Working Practices for a Lean Environment
The following working practices must be put in place before moving to a Lean environment;
1. Employee Empowerment: Employees should be empowered to make decisions and
address challenges related to their jobs.
2. Training and Development: Employees should have access to chances for ongoing
learning and development as well as training on Lean concepts and methodologies.
3. Process Mapping and Standardization: Processes should be standardized and
documented in order to identify and reduce waste, as well as to ensure quality and
consistency.
4. Performance Measurement: To discover opportunities for improvement, performance
should be measured and monitored.
5. Continuous Improvement Culture: Everyone should be encouraged to identify and
execute changes in a culture of continuous improvement.
"The most dangerous kind of waste is the waste we do not recognize." Shigeo Shingo, a well-known
Lean expert.
Remember that moving to a Lean environment demands a cultural and mentality shift, and it may
take some time for these changes to be fully implemented and accepted.
Changing to a Lean environment necessitates a cultural transformation from authoritarian to one
that emphasizes employee empowerment, continuous improvement, and collaboration. It entails
implementing work practices that are consistent with these principles (Wahab et al., 2013).
Question 4
Recommend and describe a tool or technique which can be used to analyze and improve the
performance of ‘Smoothtools’ manufacturing systems e.g. Rank-order clustering, Ishikawa
diagrams, value stream mapping etc. and explain its basic principle, how it would be applied, the
potential benefits and inhibitors to implementation.
Recommendations: Value Stream Mapping (VSM)
Value Stream Mapping (VSM) is a lean manufacturing technique for analyzing, designing, and
managing the flow of materials and information required to provide a product to a customer
(Stamm, 2008)
Basic Principle
VSM is founded on the idea of removing waste from a process. It depicts the complete
manufacturing process, identifying where value is added and waste happens. The ultimate goal is
to optimize the value stream by eliminating non-value-adding operations and improving those that
do (Brunt, 2000).
Application
The following steps should be considered when applying VSM in the manufacturing systems of
Smoothtools (Khaswala & Irani, 2001);
1. Identify the product: Select a product line, service to map, or process family.
2. Create a current state map: All the processes and steps involved in the production of
goods and services must be documented accordingly. This will include both the value
adding and non-value adding activities.
3. Assess the current state map: Bottlenecks and waste in the process must be identified.
4. Create a future state map: Consider making the process leaner by eliminating or
minimizing the observed waste and bottlenecks.
5. Implement changes: Create or design a plan to easily move from the current state to the
future state.
Potential Benefits

Improved Efficiency: VSM can significantly improve production process efficiency by
identifying and eliminating waste,

Increased Visibility: VSM delivers a clear visual picture of the manufacturing process,
which makes it easier to understand and manage production processes.

Enhanced Collaboration: Creating a value stream map fosters collaboration and
consensus among all stakeholders.
Inhibitors to Implementation

Resistance to Change: Employees may resist changes to their familiar processes and
routines.

Lack of Understanding: Employees may not fully engage in the process if they do not
grasp the objective and benefits of VSM.

Insufficient Resources: Implementing changes based on a value stream map may take
major resources, including time, money, and staff.
In summary, adopting lean manufacturing practices necessitates a thorough understanding of
various planning approaches, a commitment to level scheduling, alignment of organizational
culture with lean philosophy, and the use of effective tools for continuous improvement such as
Value Stream Mapping.
References
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