Delivering The Requirements - Ch. 12

Question 1

What could delivering the requirements include?

Answer 1

• business process change (simpler, faster, more accurate, more effective)
• people changes (redefined roles, new tasks, new skills - training, coaching, mentoring, recruitment, appraisal)
• organisational structure changes (posts disappear, new posts created, departments merged or split)
• IT system changes

Question 2

What factors should you bear in mind when deciding upon the delivery approach?

Answer 2

• Context (nature of organisation and project)
  
  • culture and philosophy
  • busienss context for change
  • project constraings
  • prioritised business needs
  • drivers for project
• lifecycle (development and implementation of solution)
  
  • SDLC (systems development lifecyles)
• approach (methods and standards used during lifecycle)
• roles
• deilverables
• techniques to be used (planning, analysing and documentation techniques).

Question 3

What is a business change lifecycle?

Answer 3

ADDIR

• Alignment
  (SEA - strategy, environment, architecture)
• Definition
• Design
• Implementation
• Realisation

All the above feed into, and are fed by, the Business Case.

Question 4

What is the waterfall lifecycle?

Answer 4

Development proceeds through a series of sequential stages, each reviewed and signed off before the next start.

• Feasibility study
• Analysis
• Design
• Development
• Testing
• Implementation

Pros:

Provides good control from a project management perspective leading to a high-quality system.

Cons:

Long-drawn-out development that does not handle change well.

Question 5

What is the ‘V’ model lifecycle?

Answer 5

Similiar to the Waterfall lifecycle but bent back on itself following the development activity in order to show the connection between the earlier developmental stages of the project and the laster testing stages.

Define ……………..Acceptance………….Ensure User Requirements Criteria Acceptance

       \                                                          /

     Design..............*System Test*...........Test
      Solution                *Criteria            *Solution       

             \                                             /

           Develop.........*Unit Test........*Test
            Solution         *Criteria         *Modules

Question 6

What is the Extended ‘V’ Model?

Answer 6

This model is used to show the range of business anlaysis work in the light of an IT solution lifecycle.

The ‘V’ Model is extended at the top of the pyramid as follows:

Analyse business………Business………….Review
needs Case Benefits

The analyst should be involved during design, development and testing in order to:

• ensure all business needs continue to be met;
• develop the process and job role definitions needing implementating alongside the IT solution;
• assess impact of proposed changes.

Question 7

What is incremental delivery?

Answer 7

Incremental delivery allows more important or urgent requirements to be implemented first, for example to meet a regulatory deadilne.

• Analysis
• Design
• Two incremental delivery phases
  
  • development
  • testing
  • implementation

Cons:

Total cost likely to be higher than in delivering complete solution in one release due to regression testing, making sure that the additional features do not cause something already implemented to stop working. Initial phase must be future-proofed to allow for later increments.

Question 8

What is Boehm’s Spiral Model?

Answer 8

The spiral model is a software development process combining elements of both design and prototyping-in-stages, in an effort to combine advantages of top-down and bottom-up concepts. Also known as the spiral lifecycle model (or spiral development), it is a systems development method (SDM) used in information technology (IT). This model of development combines the features of the prototyping and the waterfall model. The spiral model is intended for large, expensive and complicated projects.

The spiral model is based on continuous refinement of key products for requirements definition and analysis, system and software design, and implementation (the code). At each iteration around the cycle, the products are extensions of an earlier product. This model uses many of the same phases as the waterfall model, in essentially the same order, separated by planning, risk assessment, and the building of prototypes and simulations.[3]

Documents are produced when they are required, and the content reflects the information necessary at that point in the process. All documents will not be created at the beginning of the process, nor all at the end (hopefully). Like the product they define, the documents are works in progress. The idea is to have a continuous stream of products produced and available for user review.[3]

The spiral lifecycle model allows for elements of the product to be added in when they become available or known. This assures that there is no conflict with previous requirements and design. This method is consistent with approaches that have multiple software builds and releases and allows for making an orderly transition to a maintenance activity. Another positive aspect is that the spiral model forces early user involvement in the system development effort. For projects with heavy user interfacing, such as user application programs or instrument interface applications, such involvement is helpful.[3]

Starting at the center, each turn around the spiral goes through several task regions [3]:

• Determine the objectives, alternatives, and constraints on the new iteration.
• Evaluate alternatives and identify and resolve risk issues.
• Develop and verify the product for this iteration.
• Plan the next iteration.

Question 9

What is the main difference between agile and waterfall systems development approaches?

Answer 9

Agile accepts that revisiting previous steps in the development process is valid and that change, clarification of requriements etc are inevitable.

Waterfall has end-stage deliverables that are signed off, with any proposed changes being subject ot formal change control.

Question 10

What are the pros and cons of AGILE and WATERFALL approaches to development?

Answer 10

AGILE

• Pros
  
  • Adapts well to change
• Cons
  
  • emerging prototype systems may not be docuemnted properly or are not coherent.

WATERFALL

• Pros
  
  • High quality system
  • Excellent control measures in place
• Cons
  
  • Does not adapt to change well

Question 11

What are the pros and cons of buying a COTS (Commercial Off-The-Shelf) solution?

Answer 11

• Pros
  
  • Cheaper
  • Faster implementation
  • Support and maintenance readily available
  • Vendors keep software up to date
• Cons
  
  • Will not be a ‘perfect fit’ - organisation must adapt or pay for expensive customisation (partly negating one of the COTS benefits)
  • Unlikely to deliver competitive advantage