Search results

Flexible scheduling in school libraries is supported by the American Association for School Libraries (AASL) and the Association for Educational Communications and Technology (AECT). Support is based on the constructivist theory of learning and posits increased learning, collaboration, and visitations by classes, small groups, and individuals to the availability of resources during the time of need, yet there is no direct evidence to support flexible scheduling. The quantitative study sought to examine the relationship between media center scheduling on students’ academic achievement, teacher and media specialist collaboration, and class visitation in an elementary school. The researcher utilized an experimental posttest-only control group design. The point-biserial correlation was utilized to identify any relationship between groups who utilized the media center on a fixed versus a flexible schedule and criterion-referenced test scores. No significant relationship was found between scheduling patterns, student achievement, and collaboration. However, the research supported increased number of visitations by classes on a fixed schedule.

The purpose of this paper is to present a mathematical model and a new hybrid algorithm for flexible job shop scheduling problem with assembly operations. In this problem, each product is produced by assembling a set of several different parts. At first, the parts are processed in a flexible job shop system, and then at the second stage, the parts are assembled and products are produced.

As the problem is non-deterministic polynomial-time-hard, a new hybrid particle swarm optimization and parallel variable neighborhood search (HPSOPVNS) algorithm is proposed. In this hybrid algorithm, particle swarm optimization (PSO) algorithm is used for global exploration of search space and parallel variable neighborhood search (PVNS) algorithm for local search at vicinity of solutions obtained in each iteration. For parameter tuning of the metaheuristic algorithms, Taguchi approach is used. Also, a statistical test is proposed to compare the ability of metaheuristics at finding the best solution in the medium and large sizes.

Numerical experiments are used to evaluate and validate the performance and effectiveness of HPSOPVNS algorithm with hybrid particle swarm optimization with a variable neighborhood search (HPSOVNS) algorithm, PSO algorithm and hybrid genetic algorithm and Tabu search (HGATS). The computational results show that the HPSOPVNS algorithm achieves better performance than competing algorithms.

Scheduling of manufacturing parts and planning of assembly operations are two steps in production systems that have been studied independently. However, with regard to many manufacturing industries having assembly lines after manufacturing stage, it is necessary to deal with a combination of these problems that is considered in this paper.

This paper proposed a mathematical model and a new hybrid algorithm for flexible job shop scheduling problem with assembly operations.

The purpose of this paper is to solve a flexible job shop scheduling problem where alternate machines are available to process the same job. The study considers the Flexible Job Shop Problem (FJSP) having n jobs and more than three machines for scheduling.

FJSP for n jobs and more than three machines is non polynomial (NP) hard in nature and hence a multi‐objective genetic algorithm (GA) based approach is presented for solving the scheduling problem. The two objective functions formulated are minimizations of the make‐span time and total machining time. The algorithm uses a unique method of generating initial populations and application of genetic operators.

The application of GA to the multi‐objective scheduling problem has given optimum solutions for allocation of jobs to the machines to achieve nearly equal utilisation of machine resources. Further, the make span as well as total machining time is also minimized.

The model can be extended to include more machines and constraints such as machine breakdown, inspection etc., to make it more realistic.

The paper presents a successful implementation of a meta‐heuristic approach to solve a NP‐hard problem of FJSP scheduling and can be useful to researchers and practitioners in the domain of production planning.

With the continuous upgrading of the production mode of the manufacturing system, the characteristics of multi-variety, small batch and mixed fluidization are presented, and the production environment becomes more and more complex. To improve the efficiency of solving multi-objective flexible job shop scheduling problem (FJSP), an improved hybrid particle swarm optimization algorithm (IH-PSO) is proposed.

After reviewing literatures on FJSP, an IH-PSO algorithm for solving FJSP is developed. First, IH-PSO algorithm draws on the crossover and mutation operations of genetic algorithm (GA) algorithm and proposes a new method for updating particles, which makes the offspring particles inherit the superior characteristics of the parent particles. Second, based on the improved simulated annealing (SA) algorithm, the method of updating the individual best particles expands the search scope of the domain and solves the problem of being easily trapped in local optimum. Finally, analytic hierarchy process (AHP) is used in this paper to solve the optimal solution satisfying multi-objective optimization.

Through the benchmark experiment and the production example experiment, it is verified that the proposed algorithm has the advantages of high quality of solution and fast speed of convergence.

This method does not consider the unforeseen events that occur during the process of scheduling and cause the disruption of normal production scheduling activities, such as machine breakdown.

IH-PSO algorithm combines PSO algorithm with GA and SA algorithms. This algorithm retains the advantage of fast convergence speed of traditional PSO algorithm and has the characteristic of inheriting excellent genes. In addition, the improved SA algorithm is used to solve the problem of falling into local optimum.

This research provides an efficient scheduling method for solving the FJSP problem.

This research proposes an IH-PSO algorithm to solve the FJSP more efficiently and meet the needs of multi-objective optimization.

This paper aims to discuss the importance of flexible working time arrangements in the United States (U.S.). Section I creates a framework to analyse the various dimensions of working time and their impacts. It examines the availability of flexitime and its potential costs and benefits to workers and employers. Section II describes the current distribution and differential access to flexitime by workers' demographic characteristics and by industry and occupational sector. Section III analyses these data to estimate the probability that workers with a given demographic or work characteristic have access to flexitime daily schedules. The fourth and final section discusses the implications of the findings. The empirical findings reveal that many workers are gaining flexibility in the timing of their daily work schedules, but access to flexible schedules remains uneven by characteristics of workers such as gender or race and by their jobs such as skill‐level, job status and hours status. Having flexible scheduling comes at the expense of working long average hours per week, or re‐locating to part‐time or self‐employment status or “unsocial” evening shifts. One implication of this is that a public policy aimed at flexible work hours for workers benefit must seek first to spread such flexibility to those who are currently not sharing it because of their occupation, industry or other personal or labour market characteristics.

A theoretical economic model is developed to explain the disparities in flexible work scheduling observed across firms, workplaces, sectors, and time periods. Given heterogeneity in firms’ costs, the supply of flextime is determined by firms’ costs of enacting versus not adopting it. The innovative practice would be adopted if it generates net unit labor cost savings. If it is cost neutral, the extent to which the supply of flextime falls short of worker demand for it depends on the extent to which employers must accommodate employee preferences for more time sovereignty and are induced by policy incentives to switch to flexible scheduling.

A flexible manufacturing system (FMS) helps improve the system’s performance, thus increasing its overall competitiveness. FMS is an essential component of Industry 4.0 (I4.0), which has revolutionized the way firms manufacture their products. This study aims to investigate the diverse focus of the research being published over the years and the direction of scholarly work in applying FMSs in business and management.

A total of 1,096 bibliometric data were extracted from the Scopus database from the years 2001 to 2021. A systematic review and bibliometric analysis were performed on the data and related articles for performance measurement and scientific mapping on the FMS themes.

Based on co-keyword, the study reveals four major themes in the FMS field: mathematical models and quantitative techniques, scheduling and optimization techniques, cellular manufacturing and decision-making in FMSs. Based on bibliometric coupling on 2018–2021 bibliometric data, four themes emerged for future research: scheduling problems in FMS, manufacturing cell formation problem, interplay of FMS with other latest technologies and I4.0 and FMS.

The originality lies in answering the following research questions: What are the most highlighting themes in FMS, and how have they evolved over the past 20 years (2001–2021)? What topics have been at the forefront of research in FMS in the past five years (2016–2021)? What are the promising avenues of research in FMS?

In today's very competitive, dynamic and unpredictable manufacturing environments it is critical to improve manufacturing performance in order to be able to compete. Responsiveness and agility become important characteristics of manufacturing systems and organizations. Manufacturing systems must be designed optimally by taking into account responsiveness and agility related measures in order to improve effectiveness and performance. One of the important enablers of performance improvement is flexibility. It is a known fact that flexibility has a positive effect on the manufacturing system performance if it is properly utilized by the control system (usually scheduling). However, the relationship between flexibility and manufacturing system performance through scheduling is not entirely explored in the previous literature. The purpose of this paper is to investigate the effects of process plan and machine flexibilities on the scheduling performance of manufacturing job‐shops.

Effects of process plan and machine flexibilities on the scheduling performance of manufacturing job‐shops are analyzed at different flexibility levels by using the grammar‐based flexible job shop scheduling system that is developed by Baykasoğlu et al.. Three different flexibility levels are defined for process plans and machines. Four different problem sizes are evaluated according to “makespan” “machine load balance” and “mean waiting times of jobs”. Performance differences among “process plan” and “machine flexibility” levels are determined and statistically analyzed through Taguchi experimental design methodology.

It is found out after detailed analysis that the effect of machine flexibility on job shop performance is higher than the process plan flexibility. It is also figured out that after a certain level of machine flexibility, the speed of scheduling performance improvement decreases considerably.

The paper presents the interaction between flexibility and scheduling performance of manufacturing job‐shops. The findings should be taken into account while designing scheduling systems for job shops that have flexible processing capabilities.

In recent years, many firms have rediscovered the importance of scheduling on the shopfloor. Within the manufacturing functions, scheduling remains among the most important and challenging tasks that must be performed routinely. Developing a schedule involves designating the resources needed to execute each operation of the process routeing plan and assigning the times at which each operation in the routeing will start and finish execution. The trend of current scheduling technology is towards a combination of the three common approaches; OR‐based, simulation‐based and AI‐based. Presents a hybrid approach using simulation‐based scheduling and a neural network to solve the detailed scheduling problem. Develops the neural network to analyse the complex information as well as orders coming on the shopfloor, and suggests candidate scheduling rules to the simulation model. The simulation model then uses the rules to schedule the orders on hand. The work is set against a backdrop of a currently operating flexible manufacturing cell.

Project scheduling plays an essential role in the implementation of a project due to the limitation of resources in practical projects. However, the existing research tend to focus on finding suitable algorithms to solve various scheduling problems and fail to find the potential scheduling rules in these optimal or near-optimal solutions, that is, the possible intrinsic relationships between attributes related to the scheduling of activity sequences. Data mining (DM) is used to analyze and interpret data to obtain valuable information stored in large-scale data. The goal of this paper is to use DM to discover scheduling concepts and obtain a set of rules that approximate effective solutions to resource-constrained project scheduling problems. These rules do not require any search and simulation, which have extremely low time complexity and support real-time decision-making to improve planning/scheduling.

The resource-constrained project scheduling problem can be described as scheduling a group of interrelated activities to optimize the project completion time and other objectives while satisfying the activity priority relationship and resource constraints. This paper proposes a new approach to solve the resource-constrained project scheduling problem by combining DM technology and the genetic algorithm (GA). More specifically, the GA is used to generate various optimal project scheduling schemes, after that C4.5 decision tree (DT) is adopted to obtain valuable knowledge from these schemes for further predicting and solving new scheduling problems.

In this study, the authors use GA and DM technology to analyze and extract knowledge from a large number of scheduling schemes, and determine the scheduling rule set to minimize the completion time. In order to verify the application effect of the proposed DT classification model, the J30, J60 and J120 datasets in PSPLIB are used to test the validity of the scheduling rules. The results show that DT can readily duplicate the excellent performance of GA for scheduling problems of different scales. In addition, the DT prediction model developed in this study is applied to a high-rise residential project consisting of 117 activities. The results show that compared with the completion time obtained by GA, the DT model can realize rapid adjustment of project scheduling problem to deal with the dynamic environment interference. In a word, the data-based approach is feasible, practical and effective. It not only captures the knowledge contained in the known optimal scheduling schemes, but also helps to provide a flexible scheduling decision-making approach for project implementation.

This paper proposes a novel knowledge-based project scheduling approach. In previous studies, intelligent optimization algorithm is often used to solve the project scheduling problem. However, although these intelligent optimization algorithms can generate a set of effective solutions for problem instances, they are unable to explain the process of decision-making, nor can they identify the characteristics of good scheduling decisions generated by the optimization process. Moreover, their calculation is slow and complex, which is not suitable for planning and scheduling complex projects. In this study, the set of effective solutions of problem instances is taken as the training dataset of DM algorithm, and the extracted scheduling rules can provide the prediction and solution of new scheduling problems. The proposed method focuses on identifying the key parameters of a specific dynamic scheduling environment, which can not only reproduces the scheduling performance of the original algorithm well, but also has the ability to make decisions quickly under the dynamic interference construction scenario. It is helpful for project managers to implement quick decisions in response to construction emergencies, which is of great practical significance for improving the flexibility and efficiency of construction projects.