Estimating Packaged Software Implementations: The First Part of a Framework

There is no generic framework for estimating the cost of implementation and maintenance of packaged software. Each vendor and implementation partner uses its own proprietary techniques for estimations. This makes it hard to compare estimations from different sources or to build up benchmark data for public reference. A working group from the NESMA (Netherlands Software Measurement Association) has started to build a framework for estimating the effort and cost for implementation and maintenance of packaged software. For this total scope a generic cost estimation model has been conceived. The model consists of cost-drivers that determine the size of the software (size-drivers) and cost-drivers that influence the amount of work to be done (productivity drivers). In this paper we present the first step of making the generic framework applicable for estimation of the realization stage of a package implementation. It is the ambition of the Working Group to iteratively expand the scope of this framework to the total scope of implementation and maintenance.