This paper presents theoretical results related to mapping and scheduling linear workowsonto heterogeneous platforms. We use a realistic architectural model with bounded communication capabilities and full computation/communication overlap. This model is representativeof current multi-threaded systems. In these workow applications, the goal is often to maximizethroughput or to minimize latency. We present several complexity results related to both thesecriteria.To be precise, we prove that maximizing the throughput is NP-complete even for homogeneous platforms and minimizing the latency is NP-complete for heterogeneous platforms.Moreover, we present an approximation algorithm for throughput maximization for linear chainapplications on homog...