The paper is based on the assumed affinity between planning and Information System (IS) design, which makes it warranted to transfer results arrived at in planning theory to our field of IS design and implementation, at least as first tentative hypotheses. The basic notion is that alternative procedural features of planning or IS design have a definite impact upon the implementability of plans or information/data systems. The paper puts forward and discusses ten conjectures aboout the influence often procedural features of lS design upon IS implementability.