The divergence over the years or research paradigms addressing the production planning problem has led to the development of an extensive set of techniques, each of which can address a particular aspect of the practical problem and none of which provides a complete Solution. In particular most approaches fail to. address the circular, non-linear dependency between resource utilization, lead-times and safety stocks. We present a non-linear programming formulation of the integrated problem using clearing functions that determines a work release schedule guaranteeing a specified service level in the face of stochastic demand We introduce an iterative heuristic solution procedure that solves a relaxed LP approximation of the original NLP at each iteration to determine the lead-time profile to set safety-stock levels Computational experiments suggest that our proposed iterative procedure performs well relative to conventional LP models that assume fixed. workload-independent lead-times. (C) 2009 Elsevier Ltd. All rights reserved.