G063 - Requirements Specification, Design Specification

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G063 - Requirements Specification, Design
Specification System Specification
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Learning Objectives

• produced during analysis stage
• after the investigation phase and before the
  design phase
• by the Systems Analyst
• contains client requirements
• what the client would like the system to do
• what the system should do
• setting targets for the system (deliverables)

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Requirements Specification

• produced during analysis stage
• i.e. after the investigation phase
• by the Systems Analyst
• contains client requirements
• what the client would like the system to do
• what the system should do
• setting targets for the system (deliverables)

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Requirements Specification

• Will include
• input needs
• data to be stored
• entities
• processing requirements
• searches
• calculations
• output needs
• on-screen results required
• reports required

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Requirements Specification

• Also includes
• contractual terms
• deadlines
• costs
• hardware software constraints/choices
• evaluation criteria
• how fast?
• how big?
• the requirement specification is a contract
• between client developer
• success ( payment) will be determined by the
  contents

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Design Specification

• Includes
• inputs documents screens/interface
• outputs documents screens/interface
• colours, fonts, sizes including house style
• data structures
• validation rules
• error messages
• queries
• hardware software to be used
• test plan
• modelling diagrams ER, data flow, state
  transition

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System Specification

• defines the requirements for the new system
• Includes
• operational requirements
• what operations the system should carry out
• information requirements
• what information the system should provide to end
  users
• volume requirements
• how much data will be processed per
• e.g. how many transactions per day
• general systems requirements
• accuracy required, security issues, capacity for
  growth .