CONTENTS

KNOWLEDGE ENGINEERING: PRINCIPLES AND TECHNIQUES
Proceedings of the International Conference on Knowledge Engineering,
Principles and Techniques, KEPT2009
Cluj-Napoca (Romania), July 2–4, 2009, pp. 215–218
DURATION ESTIMATION OF A WORK PACKAGE
ATTILA VAJDA (1)
Abstract. Estimating the effort and duration of software work packages will be
never an exact science. Too many variables are affecting the result. This article
explores the relation between the effort and duration in software engineering
projects and presents an empirical model to predict work package duration based
on estimated effort and team size.
1. Introduction
In the early days of computing, the project total cost was influenced more by the
computer-based system costs then the software costs. Nowadays, software is the most
expensive element in most computer based systems; any cost estimation deviation in
the software development process will influence considerably the project profit and
loss. Several studies [1], [2], [3] demonstrated that grand majority of software development
projects are finished over budget and 30% of large projects are never finished.
No wonder that project cost estimation became crucial, challenging aspects of the
software development process and theme of many researches focusing on minimizing
the gap between the forecasted and real software project costs. Related to project
cost estimations, several researches were done already starting with 1965 (Nelson),
then in the 70s the SLIM model was created by Putnam and Myers, in the 80’s the
PRICE-S model by Park, the SEER by Jensen, the COCOMO by Boehm, in the 90’s
the Checkpoint by Jones [4]. The estimation models, techniques resulted form the
researches are numerous, some are sophisticated mathematical and statistical models,
and others are expert system based [5]. Most of them are calibrated for medium and
long term projects, only a very few can be adjusted for small projects performed by
small teams. Many people work on small projects, which are generally defined as
a staff size of a couple of people and a schedule of less than six months. Because
the estimates for these small projects/work packages (WP) are highly dependent on
the capabilities of the individual(s) performing the work, the best approach is to be
estimated directly by those assigned to do the work. In the reality this is not always
possible, and usually the project effort estimation is performed by a single person
who can be the technical leader or a senior developer. Then the project duration is
2000 Mathematics Subject Classification. 68N30.
Key words and phrases. project duration, effort estimation, software engineering.
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c○2009 Babe¸s-Bolyai University, Cluj-Napoca