Are you still using function points for estimating the size of Package Implementation?
Package Points is the buzzword in Oracle Practice now at Infosys Technologies Ltd for sizing an implementation project for the reasons which I am putting forward based on my experience in involving in sizing many development and package implementation projects.
Function Point Methodology is a universally accepted size measure for any software project which takes into consideration a user view of requirements while sizing. However, package implementation projects have certain characteristics which hinder the effective usage of FP methodology for sizing. Implementing an ERP mostly involves configuring certain parameters in the package and custom development is only a part of the project. Also, implementation projects can be done in partial life cycles. For example, scoping or discovery can be done a vendor A and downstream implementation by vendor B. Or Discovery can happen once for the entire client organization and implementation can happen in multiple phases. In view of the above characteristics, Package Points is a better fit for sizing implementations as it differentiates size of configuration work and custom development work; it addresses partial implementation life cycles also. Often Size is used as an input to decide the cost of implementation due to which the above parameters if not addressed properly can shake the confidence of the estimates on either side.
Package Points Methodology also scores high in terms of usability when compared to Function Point Methodology. A Project Manager or an Implementation Consultant needs to be enabled enough on either methodology to derive accurate estimates for a project. Function Point methodology seems to be more complicated in terms of understanding and arriving at the five components -- External Inputs, External Outputs, External Inquiries, Internal Logical Files and External Interface Files. Understanding Record Element Types still remains a difficult job for many project managers. Without thoroughly understanding these concepts, it’s highly improbable that an accurate estimate of FP size can be arrived at. To use FP methodology, every Project Manager has to be trained thoroughly before put into the task of estimation. On the other hand, Package Points methodology is designed in such a way that the underlying framework and the calculations need not be understood by every user of the methodology. A user just needs to know what are the functionalities along with setups to be done on the package, life cycle tasks the project involves and client complexity parameters. With these inputs, he/she can derive the size of the implementation. So, a user of the methodology doesn’t require being an expert nor formal training on the methodology to use it for sizing.
Please post your views on the Package Points methodology especially in comparison with other popular techniques available in the industry or from your experience.
Other blogs -