System Analysis: Feasibility Study and Lifecycle Models

System Analysis 1
System Analysis

System Analysis 2
Contents
Task 1..........................................................................................................................................................3
1.1 Evaluate difference systems lifecycle models [1][3]..........................................................................3
1.2 Discuss the importance of following a procedural/staged lifecycle in a systems investigation [2]....7
Task 2..........................................................................................................................................................9
2.1 Discuss the components of a feasibility report [4][5][6]....................................................................9
Technical Feasibility.............................................................................................................................9
Operational Feasibility.........................................................................................................................9
Time Feasibility..................................................................................................................................10
Legal Feasibility..................................................................................................................................10
Economic Feasibility..........................................................................................................................10
2.2 Assess the impact of different feasibility criteria on systems investigation.....................................11
Task 3........................................................................................................................................................13
3.1 Undertake a system (Adroit Ad System) investigation to meet business needs for the given
scenario.................................................................................................................................................13
3.2 Use appropriate systems analysis tools and techniques to carry out a system investigation in
relation to the given scenario................................................................................................................15
Techniques for System Evaluation.....................................................................................................15
Tools for System Evaluation...............................................................................................................16
3.3 Create documentation to support a system investigation in relation to the given scenario...........17
Problems and Opportunities..............................................................................................................17
Stakeholders......................................................................................................................................18
Data Collection..................................................................................................................................18
Entity Relationship Diagrams.............................................................................................................19
A sample ER diagram for Adroit Ads would have the following actors..............................................20
3.4 Evaluate how user and system Requirements have been addressed..............................................21
References.................................................................................................................................................23

System Analysis 3
Task 1
1.1 Evaluate difference systems lifecycle models [1][3]
All companies need a perfect software development lifecycle model. It is necessary for project
success. Adroit Ads needs to define its software development lifecycle model to deliver high
quality results consistently. Choosing the right software development model is a concern for
most companies. Even Adroit Ads should pick a system that meets its requirements perfectly.
There are several different types of software developing life cycles:
1) Agile development
2) Waterfall model
3) V-shaped model
4) Evolutionary prototyping
5) Spiral model
6) Iterative and incremental method
Each of these SDLC models has unique advantages and drawbacks.
If Adroit Ads wants a simple lifecycle model, they should opt for the waterfall model. This is a
linear sequential model in which progress flow downwards. For a new phase to begin, the
previous phases should have been completed. If the project doesn’t have changing or evolving
requirements, the waterfall model would be an ideal pick.
Benefits of this model are:
1) This is a structured approach
2) Useful in planning and scheduling projects

System Analysis 4
3) Verification is required at each stage.
4) Every phase has specific deliverables
Drawbacks in this model would be as follows:
1) Expensive model
2) Difficult to rollback
3) Requirements should be frozen at an earlier stage
The V-Shaped model is an extension of the original waterfall model. Instead of moving in a
linear fashion, processes take the shape of a “V”. early test planning differentiates the V-Model
from the waterfall model.
Benefits of the V-Model are:
1) Verification and validation happens at an early stage
2) If requirements are clearly understood, this model proves to be very useful.
3) Better chances of success than the waterfall model
Unfortunately, the V-Model is not as flexible as the waterfall model. Adjusting scope within the
project can be expensive and difficult.
Prototyping model revolves around the process of developing prototypes for a requirement. To
be more precise, incomplete versions of the program are carefully developed. This is an
important activity in this SDLC model. By visualizing several software components, gaps in the
development lifecycle can be eradicated. There are several different types of prototyping:
incremental, evolutionary, throwback and extreme.
Benefits of this model are:

System Analysis 5
1) Reduced cost and time to develop software
2) Improved user involvement
Drawbacks of this model are:
1) Developers may misunderstand user requirements
2) Every prototype needs excessive development hours
The spiral model combines several SDLC models. It includes both prototyping and design
stages. It reaps the benefits of bottom-up and top-down concepts. The model favors complicated
projects. It breaks down planning, risk assessments and development to stages. If a huge system
needs to be developed in small stages, this model proves to be useful.
Benefits of this model are:
1) Estimates on time and cost become realistic.
2) Work oriented issues can be spotted at an earlier stage.
3) Developers show early involvement.
4) Risks in the system can be managed
Drawbacks of this model are:
1) Huge amount of cost and time should be invested to reach a complete product.
2) Teams should have special skills
The iterative and incremental model overcomes several weaknesses in the waterfall model. It
begins with a clear plan and ends with maintenance. The best thing about this model would be its
iterative cycles. Small portions of the product are developed in increments.
Benefits of this model are:

System Analysis 6
1) Business value can be achieved at an earlier stage
2) Scarce resources can be used effectively
3) Change requests can be entertained easily
4) Problems will be detected at an earlier stage.
Drawbacks of the system are:
1) Needs heavy documentation
2) A standard set of tasks/processes should be followed
3) More customer involvement is necessary
Agile development is an improved version of iterative and incremental development. It involves
the collaboration of various cross-functional teams. Agile development works well with all kinds
of projects. It relies on interactive customers. What makes agile development interesting would
be “Change”.
Benefits of the model are:
1) The final product meets most customer requirements
2) Customers have the freedom to change requirements at any time.
3) Face to face talks and continuous inputs make project development interactive
Drawbacks of the model are:
1) Scalability
2) Documentation has to be done at each stage
3) Special skills are required from team members