Project Life Cycles

System development life cycle Waterfall model Spiral model Whirlpool model Rugby model OMG model

Waterfall model - intermediate reports - go/nogo intervals Project proposal report Functional specifications Feasibility report design specifications program specifications code system performance tests audit , feed-back project definition system study design programming Installation - intermediate reports - go/nogo intervals Post Imple- mentation

evaluate alternatives identify , resolve risks Boehm’s Spiral Model progress through steps determine objectives, alternatives constraints evaluate alternatives identify , resolve risks Risk Analysis Risk Analysis Risk Analysis operational prototype prototype 2 prototype 1 simulation requirements plan life cycle plan models Benchmarks concept of operation Software design integration tests and plan Design validation and verification detailed design coding Plan next phases integration tests Prototype based implementation

Whirlpool model Project proposal report Functional specifications Feasibility report design specifications program specifications code system performance tests audit , feed-back project definition system study design programming Installation Post Imple- mentation After each phase a quick review of the previous phases is made

OO-life cycle With the increasing complexity of the systems, the structured techniques suffer from two illusions: The analyst knows everything and understands the problem completely before implementation starts The users read the system analysis report and approve it

OMG-model (Object Management Group ) Facts: System requirements are not fully known at the start knowledge of the system grows during development better develop a system incrementally start with some core functions analysis object modelling full system definition design construction coordination and reuse

OMG Project Management Iterative style develop a series of solutions to a problem , each of them closer to satisfying the requirements ( also called : evolutionary development ) Incremental style Builds system functionality a little at a time. The results are not entire solutions. Matthew Pittman proposes iterative analysis and design combined with incremental development Problem is managing the reuse (by design , not by accident) How can such a project be estimated , tracked , controlled

The Waterfall Model

Waterfall model - intermediate reports - go/nogo intervals Project proposal report Functional specifications Feasibility report design specifications program specifications code system performance tests audit , feed-back project definition system study design programming Installation - intermediate reports - go/nogo intervals Post Imple- mentation

Project definition What do we want to accomplish ? - solve a new problem - incorporate new requirements - improve existing system Is a new system the best solution ? Who will be involved ? Organizational problem

System study : functional specs Objective: What is the problem ? Responsibility: The user Execution: Top-down technique 1. Activities: just a few sentences 2. Logical operations ( processes): for each activity 3. Details and definitions: rules, actions, controls , forms 4. Detail information: object, units, begin and end, classes, names

System study : functional specs 2 The problem definition report includes: For the input: form point of time and frequency origin responsibility For the output: type and layout destination usage Furthermore: reasons for realization financial advantages constraints and borders of the system

System study : The feasibility study Responsibility from this phase on in the ICT-department study of the existing system borders of the new system links with other systems study of different solutions division in subsystems applicability of packages estimation of personnel requirements cost-benefit analysis The report allows the steering committee to: - fix timings - final decision

Design : general What must be done to solve the problem? function analysis inventory of the data elements data dictionary logical model of the system ( data analysis ) major algorithms compose the working groups planning per department

Design : Detailed - interfaces with other systems - controls and checking - privacy and security aspects - hardware specifications - job flow design - Physical database design - high-level program design Detailed system and design specification

Programming and Implementation Program design diagrams code tests documentation data conversion procedure development user training - Program specifications - Code

Installation Installation of the hardware Install security procedures Tests in operational environment Training operations department Take-over in user department and EDP-department Operational - User documentation - Operations documentation

Post-implementation AUDIT compare actual system with projected budget and timing evaluate actual operation cost evaluate user satisfaction evaluate security MAINTENANCE establish hardware maintenance procedures test security plan establish change management procedures