Are you an EPFL student looking for a semester project?
Work with us on data science and visualisation projects, and deploy your project as an app on top of GraphSearch.
Concept
Putnam model
Summary
The Putnam model is an empirical software effort estimation model.
The original paper by Lawrence H. Putnam published in 1978 is seen as pioneering work in the field of software process modelling.
As a group, empirical models work by collecting software project data (for example, effort and size)
and fitting a curve to the data. Future effort estimates are made by providing size and calculating the associated effort using the equation which fit the original data (usually with some error).
Created by Lawrence Putnam, Sr. the Putnam model
describes the time and effort required to finish a software project of specified size.
SLIM (Software LIfecycle Management) is the name given by Putnam to the proprietary suite of tools his
company QSM, Inc. has developed based on his model. It is one of the earliest
of these types of models developed, and is among the most widely used. Closely related software parametric models are
Constructive Cost Model (COCOMO),
Parametric Review of Information for Costing and Evaluation – Software (PRICE-S), and
Software Evaluation and Estimation of Resources – Software Estimating Model (SEER-SEM).
While managing R&D projects for the Army and later at GE, Putnam noticed software staffing profiles followed
the well-known Rayleigh distribution.
Putnam used his observations about productivity levels to derive the software equation:
where:
Size is the product size (whatever size estimate is used by your organization is appropriate). Putnam uses ESLOC (Effective Source Lines of Code) throughout his books.
B is a scaling factor and is a function of the project size.
Productivity is the Process Productivity, the ability of a particular software organization to produce software of a given size at a particular defect rate.
Effort is the total effort applied to the project in person-years.
Time is the total schedule of the project in years.
In practical use, when making an estimate for a software task the software equation is solved for effort:
An estimated software size at project completion and organizational process productivity is used.
Official source
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.