The stochastic knapsack problem

The authors consider a knapsack with integer volume F which is capable of holding K different classes of objects. An object from class-k has integer volume b_k, k=1, . . . ,K. Objects arrive randomly to the knapsack; interarrivals are exponential with mean depending on the state of the system. The sojourn time of an object has a general class-dependent distribution. An object in the knapsack from class-k accrues revenue at a rate of r_k. The problem is to find a control policy in order to accept/reject the arriving objects as a function of the current state in order to maximize the average revenue. Optimization is carried out over the class of coordinate convex policies. Among other results, for the general case of K classes, the authors consider the problem of finding the optimal static control, where for each class a portion of the knapsack is dedicated