Introduction to SSADM

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Introduction to SSADM

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Introduction to SSADM

• What is SSADM?
• Why is SSADM Used?
• How is SSADM Controlled in the UK?
• What are the Major Tools of SSADM?
• How is SSADM Structured?

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What is SSADM?

• Structured Systems Analysis and Design Method
  (Version 4)
• SSADM is sometimes thought of as a cookbook
  approach to the analysis and design stages of the
  systems development lifecycle

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Why is SSADM Used?

• Because it Works (Sometimes!)
• Government Departments have to use it
• Contractors for the Government have to use it
• Industry Standards

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How is SSADM Controlled in the UK?

• Management- Central Computing and
  Telecommunications Agency
• Maintenance Development- Design Authority
  Board
• Documentation- National Computer Centre

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What are the Major Tools of SSADM?

• Logical Data Modeling
• Data Flow Modeling
• Entity/Event Modeling

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Logical Data Modeling
Customer Order Part
Order_Line
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Data Flow Modeling
Customer
Customer and Order Details
1 Accounts Check Customer Details and Create
Order
Valid Order Details
D1 Orders
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Entity/Event Modeling
Customer First Order Main Life Outstanding Pla
ced Cycle Balance 0 and No Orders
for 6 Mths Detail Changes Balance
Changes Detail Change Balance Change
Nam O Addr O Tel O Pymnt O Order
O Made Accptd
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Three Interdependent Views
The Business

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How is SSADM Structured?
Feasibility Study Requirements
Analysis Requirements Specification Logical
System Specification Physical Design
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Module 1Feasibility Study

• A high level analysis of a business area to
  determine whether a system can cost effectively
  support the business requirements

Stage 0 Feasibility
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Module 2Requirements Analysis

• Modeling the current system and deciding which
  way to go using LDS and DFDs

Stage 1 Investigation of Current Environment Sta
ge 2 Business System Options
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Module 3 Requirements Specification

• The selected way to go is developed and refined,
  ELHs introduced

Stage 3 Definition of Requirements
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Module 4 Logical System Specification

• What hardware, software platform
• Design of detailed program logic, i.e.. what the
  programs have to do

Stage 4 Technical System Options Stage
5 Logical Design
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Module 5Physical Design

• Logical and Technical Specifications are used to
  produce a physical database design and a set of
  program specifications, i.e. how the programs
  should work

Stage 6 Physical Design