Abstract. We study here a combinatorial problem that is motivated by a genre of architecture-independent s c heduler for parallel computations. Such schedulers are often used, for instance, when computations are being done by a cooperating network of workstations. The results we obtain expose a control-memory tradeo for such s c hedulers, when the computation being scheduled has the structure of a complete binary tree. The combinatorial problem takes the following form. Consider, for each i n teger N = 2 n , a family of n algorithms for linearizing the N-leaf complete binary tree in such a w ay that each nonleaf node precedes its children. For each k 2 f 1 2 : : : n g, t h e kth algorithm in the family employs k FIFO queues to e ect the linearization, in a manner speci ed later (cf., 1], 5] -7]). In this paper, we expose a tradeo between the number of queues used by e a c h o f t h e n algorithms | which w e view as measuring the control complexity of the algorithm | and the memory requirements of the algorithms, as embodied in the required capacity o f t h e largest-capacity queue. Speci cally, w e p r o ve that, for each k 2 f 1 2 : : : n g, the maximum per-queue capacity, call it Q k (N), for a k-queue algorithm that linearizes an N-leaf complete binary tree satis es