WHAT IS A DSS ?
Gorry and Scott-Morton’s:
“A model based set of procedures for processing data and judgment
to assist a manager in his decision making.”
According to them, to be successful, such system must be:
- Simple
- Robust
- Easy to control
- Adaptive
- Complete on important issues
- Easy to communicate with
Implicit in the definition is the assumption that :
- The system is computer-based.
- The system serves as an extension of the user’s problem solving
capabilities.
Gorry and Scott-Morton’s definition was accepted throughout most
of the 1970’s by practitioners and researchers.
Several other definitions emerged from the literature :
Alter (1980), Moore and Chang (1980), Bonczek, Holsapple, and
Whinston (1980), Keen (1980)
The tableau below provides a good summary of their various views:
Source
DSS defined in term of
________________________________________________________________________________________________________________________________________
Gorry and Scott-Morton Problem Type, System Function(support)
Little
System Function, Interface Characteristics
Alter
Usage Pattern, System Objectives
Moore and Chang
Usage Pattern, System Capabilities
Bonczek et al
System Component
Keen
Development Process
Working definition of an ideal DSS:
A DSS is an interactive, flexible, and adaptable CBIS that utilizes
decision rules, models, and model base coupled with a comprehensive
database and the decision maker own’s insights, leading to specific,
implementable decisions in solving problems that would not be
amenable to management science optimization models per se. Thus, a
DSS supports complex decision making and increases its
effectiveness.
Type of Control
Type of Decision
Structured
Operational
Control
Accounts
Recievable, Order
Entry
Semi –
Structured
Production
scheduling,
inventory control
Unstructured
Selecting a cover for
a magazine, buying
software, approving
loans
Support
Needed
MIS, Management
science
Managerial Control
Strategic Planning
Support Needed
Financial
management
(investment),
warehouse location,
distribution systems
Building new plant,
mergers and
acquisitions, new
product planning,
compensation
planning, quality
assurance planning
Negotiating, recruiting R&D planning, new
an executive, buying
technology
hardware, lobbying
development, social
responsibility
planning
MIS Operations,
Research models,
transaction
processing
Budget Analysis,
Short-term
forecasting, personnel
reports,
Make-or-buy analysis
Credit evaluation,
budget preparation,
plant layout, project
scheduling, reward
systems design
Management science,
DSS, ES, EIS
EIS, ES, Neural
Networks
DSS
DSS, ES, Neural
Networks
Intelligence Phase
Organizational Objectives
Reality
Examination
Search and scanning procedures
Data collection
Problem Identification
Problem classification
Problem statement
Design Phase
Validation of the model
Formulate a model
Set criteria for choice
Search for alternatives
Predict and measure outcomes
Success
Verification, testing of
proposed solution
Choice Phase
Solution to the model
Sensitive analysis
Selection of best alternative
Plan for implementation
Design of a control system
Implementation of
solution
Failure
Some Characteristics and Capabilities of DSS-I
1. DSS provides support for decision makers mainly in unstructured and
semi structured situations. DSS is different from EDP, TP and MIS.
2. Support is provided for various managerial levels
3. Support is provided to individuals as well as groups - GDSS.
4. DSS provides support for interdependent as well as sequential
decisions
5. DSS supports all phases of decision making process : Intelligence
design, choice and implementation
6. Support is provided for a variety of decision problems.
7. DSS must be adaptive over time
Some Characteristics and Capabilities of DSS - Contd.
8. DSS should be easy to use.
9. DSS improves the effectiveness of decision making (accuracy,
timeliness and quality) rather than efficiency (computer time close
form solution).
10. Decision maker has complete control over all steps of the decision
making process in solving the problems.
11. DSS leads to learning.
12. Should be easy to construct (?)
Should be easy to alter by its users.
Box 3.2: The Major Benefits of DSS
1. Ability to support the solution of complex problems.
2. Fast response to unexpected situations that result in changed
conditions. A DSS enables a thorough, quantitative analysis in a
very short time. Even frequent changes in a scenario can be
evaluated objectively in a timely manner.
3. Ability to try several different strategies under different
configurations, quickly and objectively.
4. New insights and learning. The user can be exposed to new insights
through the composition of the model and an extensive sensitivity
“what if” analysis. The new insights can help in training
inexperienced managers and other employees as well.
5. Facilitated communication. Data collection and model construction
experimentations are being executed with active users’ participation,
thus greatly facilitating communication among mangers. The
decision process can make employees more supportive of
organizational decisions. The “what-if” analysis can be used to
satisfy skeptics, in turn improving teamwork.
Box 3.2: The Major Benefits of DSS-continued
6. Improved management control and performance. DSS can increase
management control over expenditures and improve performance of
the organization.
7. Cost savings. Routine applications of a DSS may result in
considerable cost reduction, or in reducing (eliminating) the cost of
wrong decisions.
8. Objective decisions. The decisions derived from DSS are more
consistent and objective than decisions made intuitively.
9. Improving managerial effectiveness, allowing managers to perform a
task in less time and/or with less effort. The DSS provides managers
with more “quality” time for analysis, planning, and implementation.
Support Provided by DSS
DSS may provide several types of support. The following structure is based on
Alter(1). Each level of support contains and adds on the previous level (but may
also contribute to the previous level).
DSS
Provides
Raw data and status access

General analysis capabilities

Representation models (financial
statements). Casual models (forecasting
diagnosis).

Solution suggestions, evaluation

Solution selection
Answers to
Questions:
What is . . . . . . ?
What is / Why . . . . .?
What will be . . . . . .?
What will be / Why . . . ?
What if . . . . . . . ?
What is best / What is good
enough . . . . . . ?
1
Semi structured
decisions
14
Knowledge
2
For managers at
different levels
13
3
For groups and
individuals
Modeling
12
4
Ease of
construction
Interdependent or
sequential decisions
DSS
11
5
Support, intelligence,
design, choice
Evolutionary
usage
6
Support variety of
decision styles
and processes
10
Humans control
the machine
7
9
Effectiveness ,
not efficiency
8
Ease of
Use
Adaptability and
Flexibility
Components of DSS
1. Data includes database(s) which contains all the relevant data for
the problem and is managed by software called database
management system.
2. Model Management
The software package that includes financial statistical, management
science, other quantitative models that provide the system analytical
capabilities, and an appropriate software management.
3. Communication(Dialog) Subsystem
The subsystem through which the user can communicate with and
command DSS
These components contribute the software portion of the DSS. Also the
manager(or user) is considered a part of the problem solving system.
Conceptual Model of DSS
Other computer based systems
Data: external and
internal
Data
Model
Management
Management
Knowledge
manager
Dialog
management
Manager (user)
and tasks
The Capabilities of a DBMS in a DSS
- Capture/extracts data for inclusion in a database
- Quickly updates (adds, deletes, edits and changes)
- Quickly retrieves data from database for queries and reports
- Provides comprehensive data security ( protection from
unauthorized access and recovery capability)
- Handles personal and official data query
- Performs complex retrieval and data manipulation tasks based
on queries
- Tracks usage of data
The Data Management Subsystem
- DSS database
- Database management system
- Data directory
- Query facility
Internal data
sources
External data
Finance
sources
Marketing
Dialog
Model
Management
Management
Production
Extraction
Query
Decision support
Management
facility
database
Database Management
System
directory
•Retrieval
•Inquiry
•Update
•Report generation
•Delete
Other
Private
personal data
Knowledge
Data
Personnel
On Data And Database System-I
- Data external, internal and personal sources
- External data are a available on thousands of online commercial
databases, dictionaries, directories, reports, etc.
- Data for DSS needs to be frequently in the field using one of the
several methods
- Data for DSS may have problems such as: incorrect data, non timely
data poorly measured and indexed data, too many data or no data
- Large online databases such as CompuServe and Dow Jones
Information service can be a major source of DSS data.
- DSS can be programmed with third-generation languages , but it is
usually programmed with fourth-generation languages.
- Fourth-generation system include many integrated features for data
management
- Data are organized either in a relational, hierarchical or network
architecture. For many MSS relational type is preferable.
On Data And Database System - Contd.
- SQL is a standard access to relational database
- There is a trend to have DSS (and other MSS) distributed via
networks
- Distributed DSS provide the benefit of a PC and the power of a
mainframe
- Many DSS are being offered on client/server systems
- Object-oriented databases are especially suitable for complex DSS
such as those in computer integrated manufacturing
- Object-oriented databases are easy to use and fast to access. They are
especially useful in distributed DSS
- Many companies are developing an enterprise-wide approach to data
management. IBM’s Information Warehouse is an example
The model management subsystem
- Model base
- Model base management system
- Model execution , Integration and command
The ability to invoke run, change, combine and inspect models is
a key capability of DSS which differentiates it from other CBIS.
The model base management system (MBMS)
MBMS is a software system with the following functions :
- Model creation
- Using subroutines and other building block
- Generation of new routines and reports
- Model updating and changing
- Data manipulation
The MBMS is capable of interrelating models with appropriate
linkages through a database.
Models (Model Base)
• Strategic, tactical, operational
Model
• Statistical, financial, marketing, management
science, accounting, engineering, etc.
Directory
• Model building blocks
Model Base Management
• Modeling commands : creation
• Maintenance - update
Model execution,
integration and command
processor.
• Database interface
• Modeling language
Data
Dialog
Knowledge
Management
Management
Management
Examples of Components of Models
Area
Decision
Variables
Result
Variables
Uncontrollable
Variables and
Parameters
Financial Investment
Investment alternatives
and amounts.
Period and timing of
investment.
Total Profit
Rate of return
Earnings per share
Liquidity
Inflation rate
Prime rate
Competition
Marketing
Advertising budget
Product lines
Market share
Customer satisfaction
Customer’s income
Competitor’s actions
Manufacturing
Products and amounts
Inventory levels
Compensation program
Total cost
Quality level
Employee satisfaction
Machine capacity
Technology
Materials price
Accounting
Use of computers
Audit schedule
Depreciation schedule
Data processing cost
Error rate
Computer technology
Tax rates
Legal requirements
Transportation
Shipments schedule
Total transport cost
Delivery distance
Regulations
Services
Staffing levels
Customer satisfaction
Demand for services
The Model directory
- It is similar to the role of database directory.
- Contains the catalog of all models
- Contains models definitions
- Answers all questions about model’s capability and availability.
The Interface (Dialog) subsystem
The dialog component is the software and hardware that provides the
user interface for DSS.
- Deals with the human-machine interactions
- Uses action language to allow communication between user(s) and
machine.
- Uses presentation language - with graphic screen display…etc.
- Uses knowledge base including information that the user must know.
Data Management
and DBMS
Knowledge
Model Management
Management
and MBMS
Dialog Generation and
Management System-DGMS
Natural Language Processor
Input
Output
Action
Display
Languages
Languages
Terminal
Printers, Plotters
User
Overall Capabilities
•Create variety of DSS quickly and easily
•Facilitate iterative design process
General Capabilities
Ease of use
Access to a variety of
Access to a variety of analysis
For routine use,
modification and
guidance
data source, types, and
formats for a variety of
capabilities with some
“suggestion” or
construction of DSS
problems and contexts.
available.
Component Capabilities
Dialog
Data
Models
1. Variety of output formats and
Devices.
1. Variety of data forms and types.
1. Library of models to constitute a
model base : many types; maintain,
catalog, integrate; “canned”
(preprogrammed) library.
2. Variety of user input devices.
2. Extraction, capture, and integration.
2. Model building facility
3. Variety of dialog styles and ability to
shift.
3. Data access function : retrieval /
query ; report / display ;
3. Model – manipulation and use
facility
4. Support communications among
users and with builder.
4. Database management function
4. Model base management function
5. Support knowledge of users.
5. Variety of logical data view available
5. Model documentation
6. Capture, store, analyze dialogs
(tracking of dialogs)
6. Data documentation
6. Tracking of model usage
7. Flexible and adaptive dialog support.
7. Tracking of data
7. Flexible and adaptive support model
8. Flexible and adaptive data support