Metrics


What are metrics used for?
Metrics are intended to make a process more transparent by measuring and calculating appropriate variables.
This ensures that
  • the status of a process can be depicted and monitored
  • weaknesses can be identified and eliminated in the future
  • process sequences can be continuously improved thanks to the findings of metrics evaluations.

How are metrics encountered in software development?
Software metrics are generally based on primary data which can be interpreted (e.g. number of errors, review effort in hours, etc.). This data is then generally used to obtain parameters (e.g. error identification rate, agreement with planned effort) calculated according to fixed formulae.

What definitions are important in this context?
A metrics system is defined by the following:

  • Measurement time points
  • Primary data to be recorded
  • Parameters to be derived from this data
  • Evaluation criteria, e.g. comparison with specifications (e.g. permissible range)
  • Measures which are to be initiated as a function of the evaluation criteria
  • Tools for supporting recording (e.g. PROCON-PDE) and evaluation (e.g. PROCON-QDA).

When is the use of a metrics system expedient?
Use of a metrics system is expedient only if a development methodis employed and the development process is structured into individual phases. Only then is it possible to obtain, evaluate and analyze specific metrics data at predefined points in time.

The tool used in PSE is PROCON (see entry and monitoring of data in PROCON).

A further type of metrics is static code analysis
Static code analysis deals with the structure of the source code of software programs. The analysis results provide a picture of the size and complexity of the analyzed programs. A full description can be found in theme Static code analyses.

Information and support when using metrics is available from the Support Center for Effort Estimation and Metrics.


Siemens AG Österreich, Program and Systems Engineering PSE
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Last modified: 08/27/98 15:42
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