- Introduction
- B2B E-Commerce Primer
- Overall Function Point Counting and Estimation Methodology
- Benefits of Function Point Counting and Estimation
- Extensions to IFPUG CPM 4.1
- The Function Point Counting and Estimation Repository
- The Function Point Counting and Estimation Team-based Process
- Function Point Estimation Worksheet Example Segment
- Other Applications
- Internal Challenges at eSell
- Summary and Conclusions
- Final Questions to Ponder
Overall Function Point Counting and Estimation Methodology
After two years of evolution and experience with scores of projects, the following describes a typical project launch scenario that incorporated function point methodologies. Regardless of the project methodology you choose, one of the central deliverables in the project launch sequence is the project plan. Such a plan must include a comprehensive list of planned functionality, an effort and cost estimate to deliver that functionality, and a profile of the project team needed to do the job. The following overall high-level steps are followed to produce this project plan at eSell:
Convene a workshop at which the client, the client's business and customer representatives, and eSell services experts are present. Discuss the client's business processes and transactions and what problems exist that lend themselves to Web B2B solutions. Define a set of capabilities, identifying the application's ultimate end-users and detailing application functionality from the end-users' perspective. These fine-grained items of functionality are commonly called ability-to statements, because they all begin with the words "The end-user will have the ability to...." These ability-to statements are documented in a function point estimation (FPE) worksheet.
The eSell function point specialist then convenes and runs a function point estimation meeting at which the eSell technical experts on the project review the ability-to statements. The statements are examined for completeness and correctness, and an FPE worksheet is filled out. Each ability-to is sized (in FP), and the effort and thus cost to develop each ability-to is estimated.
The eSell project manager reviews the FPE worksheet, the proposed functionality, and its cost estimates with the client. The client can manage budget with trade-offs across the classical three degrees of freedom: functionality for time expended (cost) for resources required. This can be done at a very fine grain, because the FPE and the line-by-line functionality/size/effort mapping allow the client line-item-veto power over each ability-to.
When the client and team are satisfied, the project begins with the worksheet documenting the target deliverables, times, and costs for the deployment.