1. Engineering Activities In Software Development
Lecture 10
Engineering Activities In Software Development

2. Agenda
Methodologies

3. Methodology A Framework of tasks and steps to achieve our aims
A standardized way of approaching the design of an information system
A system of project management and control
A checklist of task/actions

4. Why methodology? Many large systems fail
Helps monitor and control progress and costs
Ensures tasks not overlooked
May be required for contractual reasons
Not all systems development uses a methodology

5. The pre-methodology era
Until the 1960s methodologies weren’t used
Emphasis was placed on programming skills rather than user needs
Systems usually over-ran both time and costs
Little consultation with users and poor or no documentation

6. Formal life-cycle approaches
Strict separation of System Development Life-Cycle (SDLC) stages
Waterfall model

7. SDLC Feasibility study (initial investigation) Systems Analysis
Systems Design
Implementation 
Installation
Maintenance 

8. “Hard” methodologies 1960s and 70s
Separation of logical and physical design
Perceived need to ‘freeze’ specifications
Emergence of ‘Structured Methods’
SSADM (Structured System Analysis and Design Methodology)

9. “Hard” methodologies Too rigid model Prevents iterative design
High levels of systems failure
Ignores social and human issues

10. “Soft” methodologies Prototyping & evolutionary approaches
Recognized the social as well as the technical dimension of systems use
Encourage greater user involvement
Participative design recognizes workers’ goals as well as management's
RAD (Rapid Application Development), DSDM (Dynamic System Development Model)

11. Agile methodologies Even more user involvement Test-driven development
Frequent integration
Pair development
XP (eXtreme Programming)

12. The End