ADVANTAGES & DISADVANTAGES OF

SYSTEM LIFE CYCLES

Olivia Houten

WATERFALL MODEL

The waterfall model describes a development method that is linear and sequential. Waterfall development has distinct goals for each phase of development. Once a phase of development is completed, the development proceeds to the next phase and there is no turning back.

ADVANTAGES OF THE WATERFALL MODEL

Advantages

A schedule can be set with deadlines for each stage of development .

Each phase of development proceeds in strict order, without any overlapping.

The amount of resources required to implement this model are minimal.

Documentation is produced at every stage of the software's development. This makes understanding the product designing procedure, simpler.

DISADVANTAGES OF WATERFALL MODEL

Disadvantages

Does not allow for much reflection or revision. Once an application is in the testing stage, it is very difficult to go back and change.

Small changes or errors that arise in the completed software may cause a lot of problems.

Until the final stage of the development cycle is complete, a working model of the software does not lie in the hands of the client, so you never know if it is what they asked for.

Often, the client is not very clear of what he exactly wants from the software. Any changes that he mentions in between, may cause a lot of confusion.

SPIRAL MODEL

This model of development combines the features of the prototyping model and the waterfall model. The spiral model is favoured for large, expensive, and complicated projects.

ADVANTAGES OF THE SPIRAL MODEL

Advantages

Its design flexibility allows changes to be implemented at several stages of the project.

The process of building up large systems in small segments makes it easier to do cost calculations.

The client, who will be involved in the development of each segment, retains control over the direction and implementation of the project.

The client's knowledge of the project grows as the project grows, so that they can interface effectively with management.

DISADVANTAGES OF THE SPIRAL MODEL

Disadvantages

Highly customized limiting re-usability.

Applied differently for each application.

There is a requirement for further explanation of the steps involved in the project such as breakthrough, blueprint, checkpoints and standard procedure.

The models work best for large projects only, where the costs involved are much higher and system pre requisites involves higher level of complexity.

CYCLICAL MODEL

The systems development life cycle (SDLC) is a conceptual model used in project management that describes the stages involved in an information system development project, from an initial feasibility study through maintenance of the completed application.

ADVANTAGES OF CYCLICAL MODEL

Advantages

Clearly defined stages.

Simple to understand and use.

Well understood milestones

Easy to arrange tasks.

DISADVANTAGES OF CYCLICAL MODEL

Disadvantages

It’s difficult to measure progress within stages.

Cannot accommodate changing requirements.

No working software is produced until late in the cycle.

Risk and uncertainty is high with this process model.