The primary focus of Welam's comment [Welam, Ulf Peter. 1977. On a simultaneous decision model for marketing, production and finance. Management Sci. 23 (9, May) 1005-1009.] is the criticism of the specific form of the demand function used to Damon and Schramm [Damon, William W., Richard...

The Holt, Modigliani, Muth, and Simon production scheduling model is extended to incorporate variables reflecting marketing and working capital management in a cash flow formulation. A constrained nonlinear program is dervied for which a local optimal solution is discovered employing the SUMT...