Chapter 2- Software Development Process  Product Components  Software Project Staff  Software Development Lifecycle Models

What is a software product ?

The software CD-ROM is just one of the many pieces that make up a software product

What is a software product?

Note

What Effort Goes Into a Software Product ? Artifact: any Software product component created during the life cycle Deliverable: Software product component that is created and passed on to the customer

What Effort Goes Into a Software Product?

Customer Requirements: –What features the software product should have. Specifications: –The format of specifications varies greatly –A structured document setting out detailed descriptions of the system’s functions, services and operational constraints. Schedules: –A Gantt chart is a bar chart that shows a project's tasks against a horizontal timeline Software Design Documents : –Architecture –Data Flow Diagram Test Documents : –The test plan –Test cases –Bug reports

Software Development Life Cycle Activities Architecture Design Structured by code... Source Code Implemented by Physical DFD Realized by Logical DFD Expressed in terms of Test Cases ? Verified By class.... ? Requirements System Design Detailed Design Implemen- tation Testing Requirements Elicitation Analysis

Software Project Staff Project managers –Write the project proposal & manag the schedule Architects –Design the overall systems Programmers –Write software and fix the bugs Testers –Find and report problems in the software product. Technical writers –Create paper and online documentation that comes with a software. Configuration management or builder –Put it all together into a single package QA (Quality Assurance)

Software Development Lifecycle Models Big-Bang Model –little if any planning, scheduling, or formal development process. –Testing is done when the product is complete Code-and-Fix Model (software prototyping) –starts with a rough idea of what they want, does some simple design –proceeds into a long repeating cycle of coding, testing, and fixing bugs. –At some point they decide that enough is enough and release the product. –show results immediately.

Code-and-Fix Model

Software Development Lifecycle Models Waterfall Model –Moves down a series of steps starting from an initial idea to a final product. –At the end of each step, the project team holds a review to determine if they're ready to move to the next step. –The steps are discrete; there's no overlap –Clear specification of what the product will do

Waterfall Model

Software Development Lifecycle Models Spiral Model (Barry Boehm) –Each time around the spiral involves 4 steps: 1.Determine objectives, alternatives, and constraints. 2.Identify and resolve risks and evaluate alternatives. 3.Develop and test the current level. 4.Plan the next level and decide on the approach for the next level.

Spiral Model

Software Development Lifecycle Models Agile Software Development –Iterative and Incremental development –Other names: Unified Process, Scrum, Extreme Programming, Rapid Prototyping. –Break tasks into small increments with minimal planning –Each iteration involves a team working through a full software development cycle –Routine and formal daily face-to-face communication among team members –Customer collaboration

Agile Software Development

Quiz 1.Name several tasks that should be performed before a programmer starts writing the first line of code 2.Why can the waterfall method be difficult to use? 3.When using the code-and-fix model, how do you know when the software is ready to release? 4.Which model would the software tester like?