Due to the developments in micro electronics, there is today a wider choice than ever of computer sizes and networks to choose from. There are many factors like investments, installation, system development, education, organizational consequences and many others to be taken into account when an organization faces such a decision. A model of a set of those costs has been developed along with a computer program to carry out the tedious numerical work to compare different system design alternatives. The report does not include quantitative simulations but focuses on qualitative aspects. It is shown that in contrast to the earliest computer technologies, there exists now a true minimum representing the optimal level of decentralization. For a given task distribution, this level is shifting in time towards greater decentralization.