This article explores the computerization of an organization characterized by a trial-and-error growth process, in which management by organization, by computers and then by use was successively tried and tested. Each of these approaches closely combines techniques with a distribution of roles, and responsibilities with specific expertise. The dynamics of computerization sheds light on attempts to articulate organizational design conveyed by computerization, and that which prevails in the organization. The constant adjustments observed call for the adoption, each time, of an alternative computerization logic for solving the problems encountered.