Transaction costs are believed to cue an improvement in organizational productivity, but it has not yet been investigated exhaustively. In this study we aim to propose an approach for integrated R&D project management by optimizing transactions, in particular, designing and managing intellectual interactions in off-line meetings. First, an enabling managerial framework was designed from three aspects, i.e., modes of transactions, points of discussion, and transactors. Secondly, a deduction in key activity and performance indicators was demonstrated through ethnographic observations on a series of sampled meetings. Furthermore, a method of transaction diagramming was developed. The collected data was subjected to regression analyses to evaluate the effect of these activity indicators against their performance. It was found that the explicitness in the agreements made during the meetings had a significant positive effect on the overall productivity. Furthermore, we also found that pre-meeting activities, such as proper agenda setting, appropriate selection of transactors, and the elaborate preparation of meetings, are preferred activities to increase productivity of meetings. These findings show a good correspondence to practical experiences; therefore, we concluded that the proposed approach is well functioning. These trials are oriented to foster an institutional approach for intellectual productivity management, and expected to improve the existing guidelines (e.g. PMBOK) towards open and interdisciplinary value creation project management.