Technical System Options

1
Technical System Options

• Specify technical environment
• Confirm functionality of new system
• Analyse impact on organisation
• Provide cost/benefit analyses
• Provide a stop/go point
• e.g. Like Feasibility and Business System
  Options
• Often the basis for procurement
• Enables detailed physical design

2
Technical System Option Components

• End product of Stage contains following
  documents
• Technical Environment Description (TED)
• System Description
• Impact Analysis
• Outline Development Plan
• Cost/Benefit Analysis

3
Technical Environment DescriptionHardware

• Hardware TED is generic rather than specific
• System Diagram showing layout
• number of terminals or PCs
• printers
• communication lines
• processors
• other devices
• Hardware also subject to System TED

4
Technical Environment DescriptionSystem

• Textual descriptions which may cover
• standards
• communications
• environment
• installation
• upgrade arrangements
• reliability
• serviceability
• availability
• maintainability
• software

5
Technical Environment DescriptionSoftware

• May cover following aspects
• data management software
• system recovery and dumping facilities
• operating system
• application packages
• construction software
• e.g. Programming languages, testing tools
• development environment
• access rights and security
• system sizing
• space requirements
• processing performance
• first-cut physical design

6
System Description

• Shows how option satisfies Requirements
  Specification
• Supports major decisions taken in Business System
  Options
• Includes alternative systems with trade-offs
• Shows degree to which system requirements met
• NB. It is also important to show which
  functions/facilities will not be provided
• Includes
• Required System Logical Data Model
• Function Definitions
• Requirements Catalogue (showing solutions based
  on the option)

7
Impact Analysis

• Explains effects on user environment
• Should cover
• organisation and staffing
• changes in user operating procedures
• implementation considerations such as conversion
• savings
• comparative advantages and disadvantages of
  alternative TSOs
• Includes issues documented in following products
• Training Requirements Description
• User Manuals Requirements Description
• Testing Outline
• Take-on Requirements Description

8
Outline Development Plan

• Enables development costs to be estimated
• Shows next module in detail
• Shows outline of subsequent plans
• Should contain time, resource and cost estimates
  for
• physical design
• program design and programming
• procurement
• system testing
• implementation

9
Cost/Benefit Analysis

• Most objective way to compare merits of options
• Cost/Benefit Analysis should cover
• development costs
• operating costs
• tangible benefits and displaced costs
• i.e. Current system costs eliminated by new
  system
• cost containment
• Intangible benefits
• improved product quality
• improved service to customers
• greater job satisfaction for employees
• improved management information

10
Considerations for TSOs

• Staff involved
• External and internal constraints
• Development of outline Technical System Options
• Refining Technical System Options
• Making the selection
• Documenting the selection

11
Staff Involved in Technical System Options

• Project board
• often assesses TSOs and makes selection
• may terminate project if no suitable option found
• Project Manager or Module Manager
• finalises TSOs
• finalises and presents TSOs
• Analysts
• research and document requirements
• formulate TSOs for presentation

12
The Decision Makers

• Usually project board
• Special review group including users and IT
  specialists
• Standard QA review group
• Consensus approach
• selection made by project board based on user
  views

13
External Constraints

• Imposed from outside the project
• Typical constraints include
• delivery dates
• total costs
• hardware and/or software preferences

14
Internal Constraints

• Set within the project by the user
• Typical constraints include
• mandatory facilities
• e.g. On-line access, word processing
• minimum service levels
• e.g. Mean time between failures, maximum time
  to restore system, availability, reliability
• data storage space requirements
• critical timing criteria
• information objectives
• operating environment conditions
• security requirements
• interfaces to other Information Systems

15
Making the Selection

• Present TSOs
• NB. Presentations frequently made to users as
  well as Project Board
• Prepare carefully for presentation
• provide amplification and answer queries
• record significant comments
• Often selection chosen is hybrid of options
• document the selection
• record reasons for selection
• Update selected Technical System Option
• Update associated Technical Environment
  Description

16
Further Activities

• Develop Application Style Guide from Installation
  Style Guide
• Service Level Requirements become the basis for
  Service Level Agreements
• Physical design will be based on the Technical
  Environment Description