The selection of software can be greatly aided by the application of information science concepts. This is particularly well demonstrated in the choice of a text retrieval system and two case studies illustrating this fact are presented. The case studies provide contrasting user environments for analysis, enabling comparison between a project-based, matrix organisation and the more rigid, line-management structure. The differing requirements for a text retrieval package are investigated with particular emphasis on potential uses of the software within each organisational framework The constraints of the user environment demonstrated to play a major role are existing hardware and software, together with the mechanisms of information flow apparent in each company.Whilst the functional capabilities of the software are taken into consideration, the working environment and the needs of the users are seen to be of greater significance in the final choice of a system, regardless of organisational structure