Mingang Cheng

Simulated annealing algorithm for scheduling problem in daily nursing cares

In most Japanese hospitals, different nurses handle the pre-assigned nursing cares in different ways, which directly affect the quality of nursing cares. To our knowledge, there has been less attention on ensuring that nurses provide nursing cares in a timely and accurate fashion. Consequently, in this paper, considering the similarities to the traditional job shop scheduling problems, we will model the daily nursing care scheduling problems and propose an efficient scheduling method based on simulated annealing algorithm. By iteratively local searching based on simulated annealing: (1) permutating the tasks from one nurse to another and (2) permutating the sub tasks handled by a nurse from its original position to another new one, the proposed method is evaluated to be applicable to the nursing care scheduling problems (providing comprehensive, coordinated and cost effective nursing cares to patients).

Simulated Annealing Algorithm for Daily Nursing Care Scheduling Problem

Nursing, with the primary mission to provide quality services to patients, is accompanied by a serial of activities like patients assessment, outcomes identification for patients. In general, there has been less attention on ensuring that nurses provide nursing cares in a timely and accurate fashion. Consequently, in this paper, considering the similarity to the traditional job shop scheduling problems, we will model the daily nursing care scheduling problems and propose an efficient scheduling method based on simulated annealing algorithm. By the comparison of several nursing care plans obtained by the dispatching-rule based methods (which have been recognized to be the implementation of human thoughts), the proposed method is evaluated to be applicable to the nursing care scheduling problems (providing comprehensive, coordinated and cost effective nursing cares to patients).

Online Rescheduling in Semiconductor Manufacturing

Semiconductor manufacturing is mainly characterized by diversity of products, different process types, and random failures. It is extremely difficult to solve scheduling problems due to high frequency of disturbance occurrence. This paper proposes a new approach for the online manufacturing rescheduling method. Instead of having a dispatching process based on dispatching rules once again, we revise the existing schedule based on message passing principle once the disturbance occurs, and improve the performance of the revised schedule by the introduction of a quick local search according to permutations of processes on semi-critical paths. The proposed method can release the influence of disturbances in less than 1 second, and finish rescheduling process in less than 1 minute. Through the actual problems with about 200,000 processes, this method is evaluated to be more effective for actual manufacturing than the dispatching-rule based methods, some of which have been applied in many facilities

A fast rescheduling method in semiconductor manufacturing allowing for tardiness and scheduling stability

In semiconductor manufacturing, rescheduling problems are extremely difficult to solve in real time due to the high frequency of disturbances that occur approximately every minute. This paper proposes a new approach to online manufacturing rescheduling. Unlike the traditional methods to have a scheduling process again, we (1) revise the existing schedule to keep high schedule stability based on message passing rescheduling with operation sorting; and (2) during the manufacturing process, improve the performance of the revised schedule with the introduction of a quick local search on semi-critical paths. In actual problems with about 200,000 processes, this method can effectively accommodate disturbances in less than 1 second, and a better schedule can be obtained in less than 1 minute. This method has been demonstrated to be more effective than conventional dispatching-rule methods, some of which have been actually applied in many facilities, because it offers higher schedule stability and fewer violations of due dates

Mixed-load transportation scheduling in a floor warehouse environment

In a warehouse, efficient product transportation is required for high productivity. In general, it is recognized that mixed-load transportation can decrease the moving time to some extent. However, many scheduling methods without regard to mixed-load transportation have recently been proposed. In this respect, we propose a design for scheduling problems with mixed-load transportation handled by vehicles. The proposed method uses two well-known dispatching rules and a local search method based on a simulated annealing algorithm. Two rules are applied to obtain the initial solution while ignoring the mixed-load transportation, and the local search method is applied to improve the initial solution to obtain a semi-optimal solution in consideration of mixed-load transportation. To evaluate the applicability of the proposed system, we implemented our system with several product transportation environment. The simulation results verify the effectiveness of the proposed method.

Analysis of daily nursing care: a nursing care scheduling algorithm

Nurses are with the primary mission to provide quality services to patients up to 24 hours a day. In general, different nurses (especially between nurse experts and novices) handle the pre-assigned nursing cares in different ways, which directly affect the quality of nursing cares. In this respect, it is necessary to quantitatively elucidate the nursespsila action rules for effectively nursing instruction and quantitative evaluation of staffing levels. In this paper, we will analyze the daily nursing cares to quantitatively illustrate the implicit action rules of nurses on their provision of cares from the viewpoint of scheduling. Unlike the conventional methods mainly based on the interviews/dialogues, we hypothetically model the nursespsila action rules as some traditional dispatching rules, and elucidate the nursespsila action rules by evaluating the similarities of the actual nursing care schedules with planned nursing care ones. By analyzing several actual observed nursing cares, we quantitatively elucidate the action rules of veterans and novices, and furthermore, we compared their differences on the rules.

Online job shop rescheduling with reaction-diffusion equation on a graph

The job-shop scheduling problem (JSSP) is one of the most difficult NP-hard combinatorial optimization problems. It is extremely difficult to solve the complex job shop scheduling problems because of the disturbances of manufacturing environment. This paper proposes a new method based on the reaction-diffusion equation on a graph [Yuasa, H and Ito, M (1998)] to solve JSSP with disturbances. This method considers the operations of JSSP as the autonomous decentralized system elements. According to the definition of the local potential functions between two operations (two operations on the same machine or the same job), the original schedule can be revised to accommodate with the disturbances of manufacturing, such as machine breakdown, processing time variation, in a short time. The present method is tested for benchmark problems with disturbances.