Entity Life Histories

The entity life history (ELH) technique was originally designed to extend the available database design techniques such as E-R diagramming (chapter 16) and normalisation (chapter 15) (Robinson, 1979). Such data analysis techniques concentrate almost exclusively on a static view of the information system being modelled. ELHs, in contrast, were developed as a technique for the explicit modelling of system dynamics (Rosenquist, 1982). In this sense, the ELH may be seen as a competitor to the DFD (chapter 17) and associated process specification techniques (chapter 18). However, the ELH is more closely linked to the logical modelling ideas underlying data analysis.