Frank Vogelezang, Marcel Rispens

After two external benchmarks, the Software Application Support division decided that the only way to quantitatively manage application support was by establishing a sufficient estimate of the size of the application portfolio. Based on criteria from Gartner’s Application Benchmark a selection was made regarding which applications made up the application portfolio. Five different methods were used to size approximately three hundred applications, each with its own precision and cost efficiency: Gartner Fast FPA estimation, Backfiring from LoC for some older PL/1 and Assembler applications, detailed counts with NESMA FPA and COSMIC for newly developed systems and backtracking from budget for less important smaller applications. The size estimations were made by regular support personnel with little training in functional size measurement. A sample selection was reviewed by an experienced consultant, in order to detect possible pitfalls and ambiguities. The results from the review led to a re-evaluation of most of the FPA-estimations, with a higher precision and greater consistency. The results of these size estimates can now be used to compare parts of the portfolio and to quantitatively manage the (support of the) portfolio.


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