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beyond the software lifecycle |
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The software lifecycle provides a diachronic
view of the software process.
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Waterfallveryard projects > sebpc > lifecycle > waterfall |
| Many software development lifecycles
adopt the metaphor of the waterfall.
The word 'waterfall' is supposed to bring to mind a series of steps, with water flowing calmly and neatly from the top to the bottom. A contrived and controlled waterfall such as one might find in a public garden. Try not to think of the Niagara Falls. The waterfall approach attracts the scorn of a lot of software engineering experts, and it is often dismissed as obsolescent. However, despite its limitations, many large software projects continue to use a waterfall or modified waterfall approach. Furthermore, some proprietary CBD methods use the waterfall lifecycle, including the CBD method incorporated in CA's Cool product range.. The waterfall approach is usually highly structured, with a fixed sequence of activities. It typically combines a plan-do-test loop with a top-down path from business concerns via application concerns to technology concerns. |
Waterfall separates activities and levels - but in a fixed sequence
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| Q | What are the advantages of the waterfall approach? What are its drawbacks and limitations? |
| Q | Have you been involved in any system development projects using the waterfall approach? How effective was this approach? How well have these projects been controlled? |
| Q | Why do many software organizations and projects continue to use a waterfall lifecycle? |
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Iterative Lifecycleveryard projects > sebpc > lifecycle > iteration |
| For a programmer, iteration means repeating something until something
happens. For a systems developer, iteration means indefinitely refining
and evolving and extending something. One popular version of the iterative
approach takes the form of a spiral.
The iterative approach is supported by DSDM. Many CBD methods plump for an iterative approach, including the Select Perspective. |
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| Q | What are the advantages of the iterative approach? What are its drawbacks and limitations? |
| Q | Have you been involved in any system development projects using the iterative approach? How effective was this approach? How well have these projects been controlled? |
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Lifecycles Comparedveryard projects > sebpc > lifecycle > comparison |
| Q | When would you use a waterfall approach? When would you use an iterative approach? |
| Q | In what kinds of organization would you expect to find the waterfall approach used? In what kinds of organization would you expect to find the iterative approach used? |
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Copyright © 2001 Veryard Projects Ltd http://www.veryard.com/sebpc/lifecycle.htm |
