The usage of ISBSG data fields in software effort estimation: A systematic mapping study

• We performed a systematic mapping study over 107 papers that use ISBSG data for effort estimation.
• Usage of dependent, filtering, and independent variables in effort models is described.
• Factors that guide the selection of relevant independent variables are described.
• Influence of estimation methods in the selection of variables has been outlined.
• References that have worked with a specific independent variable are listed.

The International Software Benchmarking Standards Group (ISBSG) maintains a repository of data about completed software projects. A common use of the ISBSG dataset is to investigate models to estimate a software project's size, effort, duration, and cost. The aim of this paper is to determine which and to what extent variables in the ISBSG dataset have been used in software engineering to build effort estimation models. For that purpose a systematic mapping study was applied to 107 research papers, obtained after a filtering process, that were published from 2000 until the end of 2013, and which listed the independent variables used in the effort estimation models. The usage of ISBSG variables for filtering, as dependent variables, and as independent variables is described. The 20 variables (out of 71) mostly used as independent variables for effort estimation are identified and analysed in detail, with reference to the papers and types of estimation methods that used them. We propose guidelines that can help researchers make informed decisions about which ISBSG variables to select for their effort estimation models.