Template-Type: ReDIF-Article 1.0 Author-Name: Parinaz Vaez Author-X-Name-First: Parinaz Author-X-Name-Last: Vaez Author-Name: Mehdi Bijari Author-X-Name-First: Mehdi Author-X-Name-Last: Bijari Author-Name: Ghasem Moslehi Author-X-Name-First: Ghasem Author-X-Name-Last: Moslehi Title: Simultaneous scheduling and lot-sizing with earliness/tardiness penalties Abstract: The problem investigated in this paper is one of the simultaneous lot-sizing and scheduling problems with earliness/tardiness penalties along with the sequence-dependent setup time and cost. Minimising earliness and tardiness is of interest both in just-in-time production systems and in make-to-order ones. A mathematical model is presented similar to the travelling salesman problem. The problem objective is to determine the production lot-size and their schedules. In spite of its wide applications, this problem has not yet been reported in the literature. To solve the problem, two meta-heuristic algorithms: tabu search and ant colony system are presented. The efficiencies of the algorithms are investigated for different sets of problems. The results show that each of the ant colony system and the tabu search obtained optimal solutions for 196 and 203 problems, respectively, out of among the 333 problem instances. Despite the differences between these two methods, neither can be statistically preferred. Journal: Int. J. of Planning and Scheduling Pages: 273-291 Issue: 4 Volume: 2 Year: 2018 Keywords: scheduling; lot-sizing; earliness/tardiness; tabu search; ant colony system. File-URL: http://www.inderscience.com/link.php?id=95416 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijps:v:2:y:2018:i:4:p:273-291 Template-Type: ReDIF-Article 1.0 Author-Name: Danial Khorasanian Author-X-Name-First: Danial Author-X-Name-Last: Khorasanian Author-Name: Franklin Dexter Author-X-Name-First: Franklin Author-X-Name-Last: Dexter Author-Name: Ghasem Moslehi Author-X-Name-First: Ghasem Author-X-Name-Last: Moslehi Title: Analyses of the phase I postanesthesia care unit baseline capacity and effect of disruptions to its beds or nurse availability on operating room workflow Abstract: When there is not a free bed or nurse in the postanesthesia care unit (PACU), the patient recovers in the operating room, preventing the start of the subsequent case(s), until capacity is available in the PACU. We report some real examples of situations in which the capacity of the PACU decreases unexpectedly, and analyse their implications on the operating room workflow. For this purpose, first, different surgical suite sizes are simulated, considering the important factors observed in real time. The baseline capacities of PACU beds and nurses are determined. Then, the characteristics of some situations with less capacity than the baseline are investigated, caused by disruptions of either decreasing the number of beds or nursing hours in the PACU. For example, when the number of PACU beds in 8-OR surgical suites decreases to half of the baseline, the percentage of days with delay increases from 0.22% to 86.79%. Journal: Int. J. of Planning and Scheduling Pages: 350-372 Issue: 4 Volume: 2 Year: 2018 Keywords: operating room workflow; postanesthesia care unit beds; postanesthesia care unit nurses; capacity; disruption; analytics. File-URL: http://www.inderscience.com/link.php?id=95441 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijps:v:2:y:2018:i:4:p:350-372 Template-Type: ReDIF-Article 1.0 Author-Name: John S. Loucks Author-X-Name-First: John S. Author-X-Name-Last: Loucks Title: A survey and classification of service-staff scheduling models that address employee preferences Abstract: Scheduling service workers in operations that require staffing over long days and a long week, oftentimes 24/7, is a problem that continues to grow in importance and applicability. As research in this area progresses, proposed scheduling models are increasingly including consideration of employee preferences. Roughly 325 articles containing workforce scheduling models were examined, of which 48 (about 15%) explicitly address worker preferences. Findings suggest an upward trend over time in the number of scheduling models with preference consideration. Shift and days-off preferences are most often addressed, with task assignment, total hours scheduled, and work location preferences receiving much less attention. This study brings much needed organisation to, and hence a better picture of, the research of this type published to date. The models surveyed are classified by types of preferences considered, source of the preferences (i.e., individual or staff), and priority criterion in satisfying the preferences. Journal: Int. J. of Planning and Scheduling Pages: 292-310 Issue: 4 Volume: 2 Year: 2018 Keywords: staff scheduling; workforce scheduling; WFS; tour scheduling; scheduling models; employee schedule preferences; worker preferences; schedule preferences; shift preferences; days-off preferences; task assignment preferences; work location preferences; employee satisfaction. File-URL: http://www.inderscience.com/link.php?id=95455 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijps:v:2:y:2018:i:4:p:292-310 Template-Type: ReDIF-Article 1.0 Author-Name: Ming Chen Author-X-Name-First: Ming Author-X-Name-Last: Chen Author-Name: Subhash C. Sarin Author-X-Name-First: Subhash C. Author-X-Name-Last: Sarin Title: Material-handling-system-based input control policy for wafer fabrication Abstract: In this paper, a new input control strategy is proposed for wafer fabrication facilities. This strategy is an adaptation of workload regulating and CONWIP, and comprises of two sequential steps: 1) determination of operational lot sizes; 2) release of lots based on a material handling system-based CONLOAD approach. We show the superiority of our strategy over a CONWIP-based policy via simulation of a real-life wafer fab. An approach for determining target workload levels for the proposed strategy is also presented. Journal: Int. J. of Planning and Scheduling Pages: 311-330 Issue: 4 Volume: 2 Year: 2018 Keywords: input control; lot sizing; CONWIP; shop floor control; wafer fabrication; simulation. File-URL: http://www.inderscience.com/link.php?id=95456 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijps:v:2:y:2018:i:4:p:311-330 Template-Type: ReDIF-Article 1.0 Author-Name: Yasemin Limon Author-X-Name-First: Yasemin Author-X-Name-Last: Limon Author-Name: Meral Azizoğlu Author-X-Name-First: Meral Author-X-Name-Last: Azizoğlu Title: New heuristics for the balanced k-Chinese postmen problem Abstract: In this study, we consider a directed k-Chinese postmen problem that aims to balance the costs of the postmen, while maintaining the total cost as small as possible. We formulate the problem as a pure integer nonlinear programming model. We propose three solution algorithms that use efficient incorporation of the heuristic subtour elimination constraints. Our computational results have revealed the satisfactory performances of our heuristic solution algorithms. Journal: Int. J. of Planning and Scheduling Pages: 331-349 Issue: 4 Volume: 2 Year: 2018 Keywords: k-Chinese postmen problem; pure integer nonlinear program; heuristic solution algorithms. File-URL: http://www.inderscience.com/link.php?id=95457 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijps:v:2:y:2018:i:4:p:331-349