4:
A section that
gives an example in business of each method type and why that model is most
suitable
Waterfall and spiral lifecycles
Spiral
It is used
in big development projects and in the stages there are arranged in the shape
of a spiral, it is used when somebody wants to use a new technology
The spiral
is also another software development process, it combines pieces of the
waterfall model with the features of prototyping this model was developed to be
used for large and complicated projects which will be expensive
The process
of development will normally be closely tied to the waterfall model, both
models having similar stages
The spiral
model allows for you to keep adding improvements to the model unlike the water
model which doesn’t allow for you to go back and change the model and since the
spiral model is suited for big projects, a company is bound to make a mistake
along the way and will need them to go back and correct any mistakes, this is
why the waterfall model is no good for company which are big and are spending a
lot of money.
But using
the spiral model normally takes more time and it requires more resources then
the waterfall model.
What kind of projects are they suitable for?
Projects
which are large and will cost a lot of money and are very complicated the
spiral model looks to be suited to the larger and more important tasks and is
not suited for small projects. For example a multibillion pound company will
need to use the spiral model because the projects are big and cost a lot of
money and contain lots of important tasks
Waterfall
This
lifecycle uses a sequential method of stages and they have a clear goal for
each development stage when using this you cannot go back to the previous stage
although this waterfall model is very easy to use. The system doesn’t allow you
to go back, so if any changes need to be done to the system it is best being
done at the beginning because it is hard to go back and make the required
changes
The
waterfall method is used for software development and contains several stages which
is incorporated into the model, the several stages are, requirements
specification, design, construction/implementation, integration, testing and
debugging, installation, maintenance.
The waterfall
diagram has clear goals for the different development stages and doesn’t allow
you to skip the stages
The
waterfall model should move to a phase only when it’s previous stage is
completed and perfected if the stage is not complete then it will not allow the
analyst to move on, the waterfall model allows the user to find problems with
the system at the earlier stages and then they are able to be changed to allow
the system to work.
When working
with the waterfall model it’s hard to leave things out in the earlier stages,
because the planning process is very accurate.
What kind of projects are they suitable for?
They are
suitable to projects that have low risk in the areas of user interface and the
performance requirements, but have a high risk in budget and schedule
predictability and control.