Here you will find frequently asked questions about FPA with answers. In case you have remarks and/or additions to the answers or in case you have a question yourself, please let us know.
How expensive is it to make an FP-analysis?
The cost of making an FP-analysis is almost negligable compared to the total project-costs: about 0.5%.
What are the success factors for introducing and using FPA?
Success factors are: knowledge and experience, speed, experience data, estimation model and the right position within the organisation.
Knowledge and experience can only be obtained by thorough education of a restricted number of people and by seeing FPA as a real profession.
Speed is achieved by removing unnecessary details from FPA and concentrating on the identification of system boundaries, elementary functions and logical files.
Experience data combined with an accurate estimation model are hard to build by oneself, costing time and money.
The right position of FP-Analysts within the organisation is crucial for a successful introduction of FPA. Impressive success stories come especially from managers, controllers and purchasers who were able to better decide and manage with the information so obtained.
For what types of project is FPA useful?
FPA is useful for new developments, adaptive maintanance, implementation of COTS (ERP systems) and conversion projects. The technique of FPA can be applied with all methods and techniques of system development. Most useful for administrative systems, FPA can be used well with other types of software.
From which phase of development can FPA be applied?
FPA can be applied in every phase of software development. In earlier stages there is more uncertainty about its size. Experience data and models make it possible to convert this into a more reliable estimate of effort, duration and quality.
During a project FPA is useful to establish the size of proposed changes, to measure the progress of a project resulting in better management of the project.
When the project is finished, FPA is useful for benchmarking and planning of system management and maintenance.
Can FPA be applied without documentation?
With interviews an experienced FP-analyst is capable to arrive at an accurate estimate of size.
Is it possible to apply FPA to batch software?
The size of batch software can be measured very well. It is necessary to be able to infer functionality from technical structure. Clearly, incoming and outgoing streams can give an accurate picture of the size.
Is it possible to measure RAD/RUP/DSDM projects with FPA?
With these types of project it is less easy to keep an overview of the final product. Therefore, in these situations a prior FPA of the entire project and its increments is essential. With FPA the (higher) cost can be calculated and these can be offset against the advantages of incremental development. Advantages of incremental approaches are to be be found in higher quality and better acceptation by users.
Does a detailed FPA (with data element types and referred logical files) give better results than a global FPA?
Experience shows that assessment of the complexity of functions and logical files by the NESMA-standard yields, for all practical purposes, the same accuracy as a detailed analysis. A detailed analysis is only possible after a detailed functional design is ready and costs about 8 times as much time and effort. The detailed approach increases an idea of accuracy and thereby makes it easier to accept a plan for realization. By its later applicability and its increased duration and effort the detailed approach has discouraged many FPA initiatives.
