Online plan modification in uncertain resource-constrained environments
نویسنده
چکیده
This thesis presents a novel approach to planning under uncertainty in resource constrained environments. Such environments feature in many real-world applications, including planetary rover and autonomous underwater vehicle (AUV) missions. Our focus is on long-duration AUV missions, in which a vehicle spends months at sea, with little or no opportunity for intervention. As the risk to the vehicle and cost of deployment are significant, it is important to fully utilise each mission, maximising data return without compromising vehicle safety. Planning within this domain is challenging because significant resource usage uncertainty prevents computation of an optimal strategy in advance. We describe our novel method for online plan modification and execution monitoring, which augments an existing plan with pre-computed plan fragments in response to observed resource availability. Our modification algorithm uses causal structure to interleave actions, creating solutions without introducing significant computational cost. Our system monitors resource availability, reasoning about the probability of successfully completing the goals. We show that when the probability of completing the mission decreases, by removing low-priority goals our system reduces the risk to the vehicle, increasing mission success rate. Conversely, when resource availability allows, by including additional goals our system increases reward without adversely affecting success rate. To James, Mum, Dad and Jen, Finishing this degree would not have been possible without your love, support and encouragement. Thank you so much. xxx
منابع مشابه
Constrained Consumable Resource Allocation in Uncertain Project Networks with Fuzzy Activity Duration
متن کامل
Uncertain Resource Availabilities: Proactive and Reactive Procedures for Preemptive Resource Constrained project Scheduling Problem
Project scheduling is the part of project management that deals with determining when intime to start (and finish) which activities and with the allocation of scarce resources to theproject activities. In practice, virtually all project managers are confronted with resourcescarceness. In such cases, the Resource-Constrained Project Scheduling Problem (RCPSP)arises. This optimization problem has...
متن کاملA UNIFIED MODEL FOR RESOURCE-CONSTRAINED PROJECT SCHEDULING PROBLEM WITH UNCERTAIN ACTIVITY DURATIONS
In this paper we present a unified (probabilistic/possibilistic) model for resource-constrained project scheduling problem (RCPSP) with uncertain activity durations and a concept of a heuristic approach connected to the theoretical model. It is shown that the uncertainty management can be built into any heuristic algorithm developed to solve RCPSP with deterministic activity durations. The esse...
متن کاملROBUST RESOURCE-CONSTRAINED PROJECT SCHEDULING WITH UNCERTAIN-BUT-BOUNDED ACTIVITY DURATIONS AND CASH FLOWS I. A NEW SAMPLING-BASED HYBRID PRIMARY-SECONDARY CRITERIA APPROACH
This paper, we presents a new primary-secondary-criteria scheduling model for resource-constrained project scheduling problem (RCPSP) with uncertain activity durations (UD) and cash flows (UC). The RCPSP-UD-UC approach producing a “robust” resource-feasible schedule immunized against uncertainties in the activity durations and which is on the sampling-based scenarios may be evaluated from a cos...
متن کاملROBUST RESOURCE-CONSTRAINED PROJECT SCHEDULING WITH UNCERTAIN-BUT-BOUNDED ACTIVITY DURATIONS AND CASH FLOWS II. SOUNDS OF SILENCE: A NEW SAMPLING-BASED HYBRID PRIMARY-SECONDARY CRITERIA HARMONY SEARCH METAHEURISTIC
In this paper, we present a new idea for robust project scheduling combined with a cost-oriented uncertainty investigation. The result of the new approach is a makespan minimal robust proactive schedule, which is immune against the uncertainties in the activity durations and which can be evaluated from a cost-oriented point of view on the set of the uncertain-but-bounded duration and cost param...
متن کامل