SDLC 面试题与答案

问题 31. Explain when to use the rapid application development (RAD) model.

RAD should be used when there is a need to create a system that can be modularized in 2-3 months of time. It should be used if there's high availability of designers for modeling and the budget is high enough to afford their cost along with the cost of automated code generating tools.

RAD SDLC model should be chosen only if resources with high business knowledge are available and there is a need to produce the system in a short span of time (2-3 months). 

问题 32. Describe incremental software development life cycle model.

Incremental SDLC approach suggests construction of a partial system rather than the complete system and then builds more functionality into it. Requirements and features are prioritized and categorized and then implemented in phases, each phase based on the waterfall model. The process continues till the complete system is achieved. 

问题 33. Briefly describe the phases in the Incremental model.

Phases of the incremental model are the same as waterfall i.e. Requirements, design, implementation, testing, and maintenance.

However, instead of following the waterfall once and for all linearly, the incremental model takes a different approach. These phases are repeated incrementally as business value is delivered incrementally as well.

For every single phase and increment a waterfall model is followed. The waterfall model is then put in a cycle of increments along with verification of requirements, and design. 

问题 34. Explain the strengths of the Incremental model.

The strengths of the incremental model are:

a) Develop high-risk business features first
b) Every increment delivers an operational product
c) Customer's confidence is high as they validate every increment and provide feedback
d) Low initial delivery cost
e) Changes in requirements can be accommodated easily.
f) More flexible than waterfall. 

问题 35. Explain the weaknesses of the Incremental model.

Weaknesses of incremental model are:
a) Needs good planning and design.
b) Needs a clear and complete definition of the complete system before it can be broken down and built incrementally.
c) Integration needs are very high
d) Total cost is higher than waterfall.