Advanced Higher Computing SOFTWARE DEVELOPMENT PROCESS

Waterfall Stages Model 1. Analysis 2. Design 3. Implementation 4. Testing 5. Documentation 6. Evaluation 7. Maintenance

Iterative Stages Model Analysis of Operational requirements System specification Software Design Implementation and testing Evaluation and maintenance

Project Proposal  Sometimes known as the Problem Definition  Limitations of existing system  Company Profile  Project Requirements  Migration Routes  Budget Constraints  Used as a basis for bids/offers for developers.

Feasibility Study  Technical  Economic  Legal  Schedule  Advantages for both clients and developers.

System Investigation  Undertaken by a System Analyst  Observation  Interview  Document and data flow inspection  Establish scope, boundaries, inputs and outputs  Produces an Operational Requirements Document (ORD).

Operational Requirements Document (ORD)  Legally binding contract  Functional Requirements  Data Requirements  Physical Specification  Scope and Boundaries  Inputs and Outputs  System Prospectus

ORD: Functional Requirements  Used at the beginning of the design stage to identify the features to be present in the proposal software.  Used to validate other stages or analysed at the end of design/implementation/etc to ensure functional requirements are being met.  Used for dispute resolution between client and developer.

ORD: Scope and Boundaries  Scope: What the proposal software will be able to do.  Boundaries: The limitations of the software (what it will not be able to do).

ORD: Data Requirements  The data structures which will be used.  The amount of data which the software will generate and store.

ORD: System Prospectus  Schedule – preliminary timings and task dependencies.  Proposed Documentation.  Training required to use the software.

Development Phase  System Design:  Flow chart  Data Flow Diagram  Jackson Structured Programming  Pseudocode  Checked to make sure it matches specification and customer requirements.

Implementation and Testing  Coding and Testing  Design and Test HCI  Set up Hardware  Convert legacy files  Complete documentation and Manuals  Train Staff

Testing  Dry runs  Structured Walkthroughs  White box (Structural Testing)  Black box (Functional Testing)  Module >Sub System > Complete System

Adopting a New System  Pilot conversion  Phased conversion  Direct conversion (Sudden Death)  Parallel conversion

Maintenance  Corrective  Adaptive  Perfective  Preventative

Evaluation (Questions)  Does it meet the specification?  It is what the client want?  Is it fit for purpose?

Waterfall Model Analysis 3% Specification 3% Coding 7% Design 5% Operational and Maintenance 67% Testing 15%