Scheduling of new produt development project including multiple activity overlapping

Faster time to market for new products is important to gain price advantage and higher sales volume. Therefore, many techniques have been suggested to reduce project duration. Activity overlapping is commonly regarded as the most promosing strategy to reduce product development times In this study, a mathematical model is proposed for scheduling new product development (NPD) projects, which includes calculating optimal overlap duration between predetermined design activities, taking into account rework duration. The mathematical model aims to minimize project duration considering resource and predecence constraints and also optimal overlapping strategy.Since the problem is known as NP-hard problem, a Particle Swarm Optimization (PSO) based approach is proposed to solve the problem for the projects having different number of activity, network compexity and resource strength. Activities priorities for scheduling are represented by particles and revised serial scheme including overlapping is utilizied to transform the particle-represented priorities to a feasible schedule according to the precedence and resource constraints. The algorithm is tested using test problems which have different number of activity, network complexity and resource strength. Also, a scenario analysis is conducted taking into account downstream activity sensivity and upstream activity evolution parameter for an electronic product development project.