Issues of RE in Waterfall

Resolved by RE in Agile

Customer involvement: Customers are involved only during the beginning of requirement gathering and analysis [40] .

Customers are involved throughout the complete process.

Prioritization of requirements: Complete requirements for the full project are prioritized upfront and the prioritization is kept up through the project lifecycle, and reprioritization is arduous [47] .

Priorities are setup for all iterations that offer opportunities for getting desirable results and customer satisfaction [48] [49] .

Documentation: Totally emphasizes at properly gathering organizing and documenting all requirements and excludes any live meetings/conferences [14] .

User stories are concise and provide to-the-point explanation of user demands, obviate the need for maintaining long SRS documents.

Requirements validation:

Validation happens late in the life cycle.

Prototyping helps in providing the customer with a blueprint of the product, and therefore helps in validating the requirements [50] .

Communication:

It is a major factor in the delay and failure of software projects [40] .

It provides regular interaction with customer and among teams.

Over-scoping of requirements: It is the cause of rework, which in turn causes further investment.

Developers receive a list of features that are constantly prioritized so the chance of having to repeat allocation in projects is minimized.

Shall Argument: The worst thing of waterfall RE is “shall” argument i.e. system shall do it, etc. [46] .

Agile introduces the real time system.