CSC/ECE 517 Fall 2012/ch2a 2w3 jm
Spiral Model
A spiral life-cycle model provides incremental development, using the waterfall model for each step, with aims of managing risk by ensuring client's approval on the deliverable at the end of each iteration. This model was defined by Barry Boehm in his article A Spiral Model of Software Development and Enhancement<ref></ref> from 1986. This model was not the first model to discuss iteration, but it was the first model to explain why the iteration matters.The spiral model (Boehm, 1988) aims at risk reduction by any means in any phase. The spiral model is often referred to as a risk-driven model.
Why Spiral Model
Extreme Programming (XP) is a software development methodology created by Kent Beck during his work on the Chrysler Comprehensive Compensation System (C3) payroll project. Extreme Programming is intended to improve software quality and responsiveness to changing customer requirements. It is a one of the several types of agile software development processes. Extreme Programming is successful because it stresses customer satisfaction. Instead of delivering everything you could possibly want on some date far in the future this process delivers the software you need as you need it. Extreme Programming empowers developers to confidently respond to changing customer requirements, even late in the life cycle. Back to top
The Model
Goals
Advantages of Spiral Model
- Built-In Quality
- Overall Simplicity
- Programmer Power
- Customer Power
- Synergy Between Practices
Coding Standards – Advantages:
Reduces the amount of time developers spend reformatting other peoples’ code. Reduces the need for internal commenting. Call for clear, unambiguous code
On-Site Customer - Advantages:
Can give quick and knowledgeable answers to real development questions. Makes sure that what is developed is what is needed. Functionality is prioritized correctly
40-Hour Week – Advantage:
Most developers lose effectiveness past 40-Hours Value is placed on the developer’s well-being. Management is forced to find real solutions
Continuous Integration - Advantages
Reduces to lengthy process. Enables the Small Releases practice
Collective Ownership – Advantages
Helps mitigate the loss of a team member leaving. Promotes developers to take responsibility for the system as whole rather than parts of the system
Pair Programming – Advantages
Two heads are better than one. Focus Two people are more likely to answer the following questions: Is this whole approach going to work? What are some test cases that may not work yet? Is there a way to simplify this?
Refactoring – Advantages
Prompts developers to proactively improve the product as a whole. Increases developer knowledge of the system
Testing – Advantages
Unit testing promote testing completeness. Test-first gives developers a goal. Automation gives a suite of regression test
Simple Design – Advantages
Time is not wasted adding superfluous functionality. Easier to understand what is going on. Refactoring and collective ownership is made possible. Helps keeps programmers on track
Metaphor – Advantages
Encourages a common set of terms for the system. Reduction of buzz words and jargon. A quick and easy way to explain the system
Small Releases – Advantages
Frequent feedback. Tracking. Reduce chance of overall project slippage
The Planning Game – Advantages
Reduction in time wasted on useless features. Greater customer appreciation of the cost of a feature. Less guesswork in planning
Disadvantages of Spiral Model
Comparison with traditional waterfall model
Research Conclusion
References
Boehm, B. W.; , "A spiral model of software development and enhancement," Computer , vol.21, no.5, pp.61-72, May 1988 doi: 10.1109/2.59
External Links
http://ieeexplore.ieee.org.prox.lib.ncsu.edu/stamp/stamp.jsp?tp=&arnumber=59&isnumber=6