This paper addresses the competitive procurement of capacity-based ancillary services (AS) in unbundled markets by the Independent Grid Operator (IGO). These AS include upward frequency control, load following and the range of reserve services, which may be procured from unloaded capacity offered by both on-line and off-line sources. The capacity-based AS are prioritized in order of ascending r...

We consider the problem of on-line scheduling with non-crossing constraints. The objective is to minimize the latest completion time. We provide optimal competitive ratio heuristics for the online-list and online-time problems with unit processing times, and a 3-competitive heuristic for the general online-time problem.

We consider the on-line problem of scheduling jobs with precedence constraints on m machines. We concentrate in two models, the model of uniformly related machines and the model of restricted assignment. For the related machines model, we show a lower bound of (p m) for the competitive ratio of deterministic and randomized on-line algorithms, with or without preemptions even for known running t...

There are some problems with estimating the time required for the manufacturing process of products, especially when there is a variable serving time, like control stage. These problems will cause overestimation of process time. Layout constraints, reworking constraints and inflexible product schedule in multi product lines need a precise planning to reduce volume in particular situation of lin...