This study presents an algorithm for deriving the long-term polices of qual
ity level, price and advertisement for a product. The diffusion models and
cost functions are combined to formulate profit functions capable of determ
ining future profit trends. The algorithm first implements the optimal cont
rol theory to derive the optimal conditions of the profit function. Then th
e genetic algorithm is employed to search for the approximate solutions of
quality level, price and advertising expenditure at each period on the plan
ning horizon (life cycle). Examples of different scenarios of the model par
ameters are presented to describe the results obtained herein. Sensitivity
analysis for the major parameters is performed to specify their effects on
profits. Results in this study allow us, firstly, to obtain explicit soluti
ons simultaneously with respect to quality, price and advertising policies,
secondly, to propose an appropriate algorithm for solving the different sc
enarios of the dynamic profit function, which consists of the diffusion fun
ction and cost function, and thirdly, to enhance the long-term profit perfo
rmance via the polices proposed herein, that is the approximation of the be
st solution.