SDLC Interview Questions and Answers

Ques 21. Explain when to use the V-Shaped model.

The V-shaped model should be used for small to medium sized projects where requirements are clearly defined and fixed. The model accommodates more planning for test than waterfall but makes accommodation of changes harder than other models. The V-Shaped model should be chosen when ample technical resources are available with needed technical expertise. Since, no prototypes are produced, there is a very high risk involved in meeting customer expectations, therefore, confidence of customer should be very high in order for choosing the V-Shaped model approach. 

Ques 22. Describe prototype software development life cycle model.

Prototype SDLC models is based upon creation of a software prototype of the complete system and then refine and review it continuously till the complete acceptable system is built. 

Ques 23. Briefly describe the phases in the Prototype model.

Phases in prototype model:
Identify some requirements to begin with: Get a list of some major requirements which define the need for the new system including the main input output information.
Develop initial prototype: Develop a basic initial prototype which only has UI screens.
Review the prototype: End users and SME’s work and examine the prototype and provide feedback for improvements/enhancements.
Revise and enhance the prototype: Scope is changed based on feedback from end users and the prototype is enhanced and refined to accommodate user feedback.  

Ques 24. Explain the strengths of the prototype model.

Strengths of the prototype model are:

a) Gains customer's confidence as developers and customers are in sync with each other's expectations continuously.
b) Ideal for online systems where high level of human computer interaction is involved.
c) Very flexible, as changes in requirements can be accommodated much more easily with every new review and refining.
d) Helps the developers and users both understand the system better.
e) Software built through prototyping needs minimal user training as users get trained using the prototypes on their own from the very beginning of the project.
f) Integration requirements are very well understood and deployment channels are decided at a very early stage. 

Ques 25. Explain the weaknesses of the prototype model.

Weaknesses of the Prototype model are:

a) Focusing on the prototype can mislead developers from understanding the actual desired system.
b) End users get confused, believing the prototype to be the complete system
c) Developers might misunderstand end users objectives.
d) Developer might get too involved in prototype and deviate from the actual system that the prototype must be converted into.
e) Expensive as prototypes need a lot of effort and time. It may take a lot of work to be done for very less needed work to be achieved.