Page 114 - DCAP304_DCAP515_SOFTWARE_PROJECT_MANAGEMENT

Software Project Management

Notes Every level of the development lifecycle has a equivalent test plan. i.e. as each phase is being
worked on, a test plan is developed to organize for the testing of the products of that phase. Be
developing the test plans, we can also define the expected results for testing of the products for
that level as well as defining the entry and exit criteria for each level.
In the V-Model the test activities are spelled out to the similar level of detail as the design
activities. Software is designed on the left-hand (downhill) part of the model, and built and
tested on the right-hand (uphill) part of the model.

Notes That diverse organization may have different names for the development and
testing phases.
The communications between the left and right hand activities are shown by the lines across the
middle of the V, showing the test levels from component testing at the bottom, integration and
system testing, and acceptance testing at the top level.

Advantages

 Each phase has specific deliverables.
 Higher chance of success over the waterfall model due to the development of test plans
early on during the life cycle.

 Time concern in comparison with the waterfall model is low or even we can say 50% less.
 Works well for small projects where requirements are easily understood.
 Utility of the resources is high.

Disadvantages

 Very rigid, like the waterfall model.
 Little flexibility and adjusting scope is difficult and expensive.
 Software is developed during the implementation phase, so no early prototypes of the
software are produced.

 Model doesn’t provide a clear path for problems found during testing phases.
5.3.3 Spiral Model

The classical models do not deal with the uncertainty with the software projects. A lot risk
assessment and analysis form a part of the software development. This was first realized by
Barry Boehm, who introduced the factor of “project risk” into the life cycle model which resulted
in the spiral model in 1986 as shown in Figure 5.3.
The radial dimension represents the cumulative cost and each path around the spiral indicates
the incremented cost. The angular dimensions depict the progress made in each cycle completion.
Each loop of the spiral, clockwise from the X-axis, through 360 degrees represents one phase.
Each phase is split into four sectors namely:
 Planning: Determining aims, alternatives and constraints.
 Risk Analysis: Analyzing alternatives and identify and resolution of risks.
 Development: Product development and testing.
 Assessment: Customer review.

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