Papers by Keyword: Dynamic Scheduling

Abstract: Cloud computing is provides resource allocation which facilitates the cloud resource provider responsible to the cloud consumers. The main objective of resource manager is to assign the dynamic resource to the task in the execution and measures response time, execution cost, resource utilization and system performance. The resource manager is optimizing the resource and measure the completion time for assign resource. The resource manager is also measure to execute the resource in the optimal way to complete the task in minimum completion time. The virtualization is techniques mandatory to allocate the dynamic resource depends on the users need. There are also green computing techniques involved for enhanced the no of server. The skewness is basically used to enhance the quality of service using the various parameters. The proposed algorithms are considered to allocate the cloud resource as per the users requirement. The advantage of proposed algorithm is to view the analysis of cpu utilization and also reduced the memory usage.

Abstract: In order to survive in a competitive environment, industries are required to adopt strategies that ensure their abilities to provide their customers with a product featured by good quality, low cost and short delivery time. Short term scheduling plays a pivotal role in this context by ensuring the operations to be executed and monitored in an optimal or sub-optimal manner which guarantees the product shipping within the customers’ due dates at lower cost and/or higher utilization of resources. However, the dynamic nature of the shop floor environment causes the predictive schedules to be no longer optimal or even feasible. Frequent disruptions occurring during the execution of the predictive schedule require the operations managers to be reactive to make appropriate decision considering the new situation. Adequate research works based on integer programming are available in literature to cope with static scheduling problems, but there is a dearth in integer programming based approaches for dynamic or reactive situations. The aim of this work is to formulate a model that solves the reactive flow-shop scheduling problem subject to arrival of new orders. Objective function for makespan minimization and the comprehensive equations for predictive and reactive schedules are presented with the necessary elaboration.

Abstract: To solve the Dual Resource Constrained Job Shop Dynamic Scheduling Problem with heterogeneous workers (DRCJDSP-HW),a three-tier dynamic scheduling system including dynamic disturbance analysis, dynamic disturbance evaluation and dynamic scheduling method was constructed based on the idea of scheduling with local time window. To minimize the revision of old scheduling scheme in DRCJDSP-HW, a hybrid dynamic scheduling algorithm was proposed based on the chromosome reduction mechanism and the scheduling optimization of local job in stages. The outstanding application effect of the dynamic scheduling system and the hybrid dynamic scheduling algorithm were validated reducing the influence of dynamic disturbances effectively by simulation experiment at last.

Abstract: Scheduling the workflow in a dynamic environment is an important issues for actual application because of service resources changed dynamically . In this paper, a cost-compensation-based dynamic scheduling algorithm (CCDSA) is constructed for the dynamic service-workflows. Related rules are defined, local re-scheduling workflow is performed by judging the influence range of abnormal nodes. Comparing CCDSA with HPSO, experimental results show that CCDSA obtains satisfied solutions, and has good adaptability and stability.

Abstract: This paper presents a preliminary work on a development of dynamic job shop scheduling model. The motivation of the study comes from an urgent need for practical procedures to enable easier and accurate feedback at operational level particularly related to job shop in small and medium-sized companies. A spreadsheet-based scheduling template is formulated and modeled using Microsoft Excel. A job shop benchmark case study available in OR-Library has been chosen to demonstrate the applicability of the basic model. The preliminary result indicating that the proposed spreadsheet model needs further refinement through incorporation of dynamic factors to be obtained from industrial practitioners.

Abstract: Aimed at the real-time request of dynamic scheduling to product resource, an optimization method of parallel dynamic chain real-time available resources was put forward. Proceed from real-time tracing of resource information influencing scheduling tasks dynamic property, established a resource informations real-time tracing back and optimization model, which used module and parallel process mechanism to different kinds of real-time traced back resource information. The mechanism processed global dynamic feedback tracing for every module and optimized available resources primarily, on this basis, graded the primary available resources and gave a real-time candidate resource set. Through one example of one gear production scheduling, the methods validity was tested.

Abstract: A dynamic scheduling method for FJSP is put forward based on real-time adjustment of controllable margin, aiming at uncertain information and dynamic characteristic during practical job-shop scheduling process. Strategy and methods of dynamic scheduling adjustment are presented, which respond to real-time event. In view of practical operation condition and accuracy demands, two methods are proposed. One is rescheduling that condenses domain, the other is scheduling updating based on adjustment. Such strategy obtains dynamic robust scheduling of FJSP to ensure the real-time of algorithm, continuity and stability of scheduling schemes.

Abstract: Aiming at uncertain information and dynamic characteristic during flexible job-shop scheduling process, some kind of dynamic scheduling method for flexible job-shop scheduling problem (FJSP) is put forward based on real-time adjustment. A dynamic simulation solution mode framework is presented for FJSP. This framework is inspired by adaptive control, combined with the robust scheduling and foreseeing scheduling. It has both advantages of such two scheduling methods, and its stable and highly efficient. Preliminary scheme generation method based on foreseeing dynamics scheduling is introduced then. Foreseeing function is realized by fault-handling algorithm and dynamic simulation solver on the basis of Adaptive Genetic Algorithm (AGA).

Abstract: Among preemptive real-time uniprocessor scheduling algorithms, many researches, such as optimal and heuristic algorithms, considers only one task attribute and neglects also the variation of attributes. To understand the relations between task attributes and scheduling success ratio, we first define the sensitivity of scheduling success ratio to task attributes. Sensitivity means the intensity of variation of scheduling success ratio as task attributes varies. The paper analyzes the sensitivities of scheduling success ratio to arrival time, execution time, deadline and laxity respectively, which have close relations with scheduling. Based on the definition of sensitivity, we also define attributes influence on scheduling success ratio, which is that the greater the influence, the higher the ratio. The essence of dynamic scheduling is a scheduling based on priority, with each dynamic algorithm matching a priority table, and vice versa. It is also much easier to infer the algorithm from the priority table, which can consider several task attributes. As priority table has various designs, it can correspond to a lot of algorithms, among which, many are inefficient. In order to deal with this kind of problem, we propose a new priority table design PTBM combining deadline and laxity based on the analysis of sensitivity and influence, which makes that a task with small deadline and large laxity has higher priority. We compare PTBM with EDF, LLF and PTD through simulation. The results verify the analysis of sensitivity and influence, and it also shows that PTBM outperforms on scheduling success ratio. It needs further exploration to design more efficient priority table by analyzing more task attributes influence on scheduling success ratio, which includes criticalness, task type and so on.

Abstract: This paper in-depth analyses the existing multiprocessor dynamic scheduling algorithms for aperiodic task, andproposes a moderately grouping algorithmbased on grouping and selecting appropriate strategy for the multiprocessor system.Satisfyingthe task deadline ofthe smaller objective function value, grouping strategy give priority to the taskshared access to the resources, improving the utilization rate of resources. Based on the earliest available time between therequired task and theprocessor in system, selecting appropriate strategy will schedule the task to the processor, improvingthe processor utilization.Compared with the existing algorithms, moderately grouping algorithm has a better performance.