The document discusses software project estimation and planning. It explains that estimation requires experience with past projects to estimate resources, costs, and schedules. Project complexity and requirements that change affect estimation accuracy. The objectives of planning are to provide reasonable cost, effort, and schedule estimates, which must be updated over time. Planning also involves estimating project scope, requirements, and human and reusable resources needed. Different models can be used for problem-based estimation. Managers must decide whether to develop software internally or acquire externally.
1. Software Engineering
Estimation
The SPM begins with a set of activities
that are collectively called Project
planning
Whenever estimates are are made we
look into future concern and so there is
some degree of uncertainty in
estimation
2. Software Engineering
Observation on Estimation
PM (manager) must have the ability to
estimate
PM with the ability to know what will go wrong
before it actually does
Estimation of resources, cost and schedule
for a software requires experience of past
projects and access to historical data
3. Software Engineering
Project complexity has a strong effect
on uncertainty that is inherent in
planning.
Complexity is affected by familiarity with
past efforts
Real time projects are always complex
Project size also effect the accuracy of
the estimates
4. Software Engineering
If the requirements have been solidified
estimation is easy but if the requirement
are keep on changing estimation is
affects
5. Software Engineering
Project Planning objectives
The objectives of software project
planning is to provides the reasonable
estimates of cost, effort and schedule
These estimates are made at the
beginning of the project and must be
updated with the passage of time.
7. Software Engineering
Obtaining information necessary for
scope
Things are always hazy at the start of
the project
There must be some meetings between
customer and analyst for obtaining the
scope of project
9. Software Engineering
Resources
The 2nd task of software planning is the
estimation of resources required to
accomplish the software development effort
The development environment-----Hardware
and software tools, Reusable components
and people
10. Software Engineering
Human Resource:
The no. of people required for a software
project can be determined only after an
estimate of development effort.
Reusable Software component
Off the shelf components
Full experience components
Partial experience components
New components
11. Software Engineering
Reusable Software component
Off-the-shelf components. Existing software
that can be acquired from a third party or that
has been developed internally for a past
project.
Full-experience components. Existing
specifications, designs, code, or test data
developed for past projects that are similar to
the software to be built for the current project.
12. Software Engineering
Reusable Software component
Partial-experience components. Existing
specifications, designs, code, or test data
developed for past projects that are related to
the software to be built for the current project
but will require substantial modification.
New components. Software components that
must be built by the software team specifically
for the needs of the current project.
13. Software Engineering
Problem based estimation
EV is calculated as
EV= (Sopt+4Sm+Spess)/6
There is a very small probability that the
actual size result will fall outside the EV
15. Software Engineering
Make Buy decision:
The software managers are often faced
with the problem of make buy decision.
In some cases it is cost effective to
acquire rather than internal
development