PROMISE: A distributed DSS approach to coordinating production and marketing decisions. This paper deals with coordination of Marketing Mix and Production Planning (MMPP) in a functionally decentralized firm operating in a distributed computing environment. Each of production and marketing is assumed to have information autonomy and makes decisions separately with respect to its own local objective. In spite of the apparent need for coordination, most of the previous studies in the literature are mainly concerned with developing operations research models, ignoring the coordination issue. Based on the literature on computer-supported cooperative work and other computer-based coordination theories, this paper proposes a distributed DSS mechanism named PROduction and Marketing Interface Support Environment (PROMISE) to provide a practical coordination support for the MMPP decisions. The meta layer in PROMISE controls the problem-solving layer consisting of marketing and production decision support systems so that optimal MMPP decisions can be reached. To show the validity of our approach, PROMISE has been implemented in Visual Basic language running on local area networked Windows 95 environments. Experimental results show that the proposed PROMISE can be used to provide a practical support for coordinating the MMPP decisions.