Effort Estimate is used to denote measure of use of workforce and is defined as total
time that takes members of a development team to perform a given task. It is usually expressed in
units such as man-day/ Person-day, man-month, man-year. This value is important as it serves as basis for
estimating other values relevant for software projects, like cost or total time required to produce a
Estimation has always been one of the riskiest aspects of project or program planning.
There are many models for software estimation available and prevalent in the industry.
1)EMPIRICAL PARAMETRIC/ NON PARAMETRIC ESTIMATION MODELS
These models rely on the experience gained on previous software projects in the sense that they connect size
and effort value by means of one of the explicit function forms, by applying regression analysis method. In
doing so, most widely used are linear and exponential dependence. For example, product value measure can
be the number of code lines in the programme or another value measure used to quantify some characteristics
of the software product. Effort is usually expressed in values such as man-day or man-hour, sometimes manyear.
2) EXPERT judgement
For coordination of differing opinions among estimators, often used is one of formal
techniques like Delphi. There exist a number of Delphi technique forms. Wideband Delphi ( )encourages
those involved to discuss the problem among themselves. This technique is implemented in following steps:
1. Coordinator will acquaint every expert with project specifications and estimation manner.
2. Coordinator will call a meeting of experts to discuss the issues related to the value to be estimated.
3. Each expert will individually and independently complete the form.
4. Coordinator will call another meeting to discuss mainly the estimates that differ most from the others.
5. Experts will complete the forms again.
6. Steps 4 and 5 will be repeated until consensus has been reached.
3) ANALOGUE ESTIMATION MODELS
It is characteristic for these models that in order for estimations to be made, analogies are used between the
new project and some of the already completed ones. Comparisons are made between the suggested project
and similar projects for which data in respect of cost, time and effort are known. These models require as
much data as possible concerning implemented projects. In some aspects, this approach is systematized
expert estimation model form, since it is usually experts who decide what projects should the new project be
compared with. These techniques require determination of those project characteristics that will be looked
for as similar between this and other projects. Effort, time, cost values of these projects are used when
making estimates concerning the new project.
Please find attached a sample Size and complexity estimation technique based estimation template
for estimating ABAP development objects. ( please open this xml file in excel )