The size of an information system, product or project is the basis for all application areas such as estimating system development, measuring productivity, benchmarking and project control. Within the field of system development and management, there are several ways to measure the size. Some methods are ISO-standardized, which offers a significant advantage with respect to the global use and management of the method.

When choosing a sizing method the following criteria plays a role:

  • Person independence: it should not matter who carries out the measurement;
  • Repeatability: when the measurement is made, should not matter; the outcome must remain the same;
  • Comparability: the size of different systems should be compared with each other;
  • Independence of technology: it should not matter what technical environment the system is built. Technical aspects shall not in any way have an influence on the size to be measured. The value and appreciation a user gives an information system is often also determined without that the user has knowledge of the technical backgrounds;
  • Applicability in an early stage, the measurement should be carried out not only on delivery of the system. The sooner you can measure in the system development process, the better you can monitor productivity and budgets;
  • Simplicity: the unit should be easy to understand
  • Future-proof: also in the introduction of new technology, the data must be meaningful and directly applicable;
  • Expression of user value: the unit says something about the functionality offered to the user;
  • Expression complexity: the unit shows which (hidden) complexity processing the information contains.
  • ISO standard

In the table below sizing methods are compared to the above aspects:

 FPACOSMICMcCabeStory PointsLOCUse Case Points
= meets
0 = meets reasonable
= does not meet
Person independency
Independence of technology
Early stage
Future proof000
User Value
Expression complexity
ISO standaard