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Article
Publication date: 4 September 2009

Sarah Westbury, Meghana Pandit and Jaideep J. Pandit

This paper sets out to investigate whether demand for gynaecological theatre time could be described in terms of the time required to undertake elective operations booked for…

Abstract

Purpose

This paper sets out to investigate whether demand for gynaecological theatre time could be described in terms of the time required to undertake elective operations booked for surgery, and so help match the capacity to this.

Design/methodology/approach

A questionnaire assessed the estimates for total operation time for seven common operations, sent to surgeons, anaesthetists and nursing staff in one tertiary referral and one district general hospital (total 49 staff; response rate 58 per cent), and estimates were obtained from theatre computer logs. Average timings for each operation were then applied to cases added from clinics to the waiting list at the district general, to yield the mean demand for elective surgery, and were also applied to emergencies to estimate emergency workload. Finally these demand estimates were compared with the theatre capacity available.

Findings

The paper found no difference between the estimates of the three staff groups or between these and the theatre logs (p=0.669), nor did it find that estimates differed between the two centers (p=0.628). Including emergencies, the mean (95 per cent confidence intervals) demand at the district general was 2,438 (1,952‐2,924) min/week.

Research limitations/implications

Although the paper modelled the variation in demand using the relevant variation in operation times, any additional variation caused by differences in booking rates from clinics over time was not nodelled. The minimum period over which data should be collected was not established.

Practical implications

The paper finds that the existing capacity of 1,680 min/week did not match these needs and, unless it was increased, a rise in waiting lists was predictable.

Originality/value

The paper concludes that time estimates for scheduled operations can be better used to assess the need for surgical operating capacity than current measures of demand or capacity.

Details

Journal of Health Organization and Management, vol. 23 no. 5
Type: Research Article
ISSN: 1477-7266

Keywords

Open Access
Article
Publication date: 13 February 2020

John A. Kearby, Ryan D. Winz, Thom J. Hodgson, Michael G. Kay, Russell E. King and Brandon M. McConnell

The purpose of this paper is to investigate US noncombatant evacuation operations (NEO) in South Korea and devise planning and management procedures that improve the efficiency of…

3109

Abstract

Purpose

The purpose of this paper is to investigate US noncombatant evacuation operations (NEO) in South Korea and devise planning and management procedures that improve the efficiency of those missions.

Design/methodology/approach

It formulates a time-staged network model of the South Korean noncombatant evacuation system as a mixed integer linear program to determine an optimal flow configuration that minimizes the time required to complete an evacuation. This solution considers the capacity and resource constraints of multiple transportation modes and effectively allocates the limited assets across a time-staged network to create a feasible evacuation plan. That solution is post-processed and a vehicle routing procedure then produces a high resolution schedule for each individual asset throughout the entire duration of the NEO.

Findings

This work makes a clear improvement in the decision-making and resource allocation methodology currently used in a NEO on the Korea peninsula. It immediately provides previously unidentifiable information regarding the scope and requirements of a particular evacuation scenario and then produces an executable schedule for assets to facilitate mission accomplishment.

Originality/value

The significance of this work is not relegated only to evacuation operations on the Korean peninsula; there are numerous other NEO and natural disaster related scenarios that can benefit from this approach.

Details

Journal of Defense Analytics and Logistics, vol. 4 no. 1
Type: Research Article
ISSN: 2399-6439

Keywords

Article
Publication date: 26 July 2018

Dongwook Kim, Dug Hee Moon and Ilkyeong Moon

The purpose of this paper is to present the process of balancing a mixed-model assembly line by incorporating unskilled temporary workers who enhance productivity. The authors…

Abstract

Purpose

The purpose of this paper is to present the process of balancing a mixed-model assembly line by incorporating unskilled temporary workers who enhance productivity. The authors develop three models to minimize the sum of the workstation costs and the labor costs of skilled and unskilled temporary workers, cycle time and potential work overloads.

Design/methodology/approach

This paper deals with the problem of designing an integrated mixed-model assembly line with the assignment of skilled and unskilled temporary workers. Three mathematical models are developed using integer linear programming and mixed integer linear programming. In addition, a hybrid genetic algorithm that minimizes total operation costs is developed.

Findings

Computational experiments demonstrate the superiority of the hybrid genetic algorithm over the mathematical model and reveal managerial insights. The experiments show the trade-off between the labor costs of unskilled temporary workers and the operation costs of workstations.

Originality/value

The developed models are based on practical features of a real-world problem, including simultaneous assignments of workers and precedence restrictions for tasks. Special genetic operators and heuristic algorithms are used to ensure the feasibility of solutions and make the hybrid genetic algorithm efficient. Through a case study, the authors demonstrated the validity of employing unskilled temporary workers in an assembly line.

Details

Assembly Automation, vol. 38 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 13 February 2007

Juha‐Matti Lehtonen, Jaakko Kujala, Juhani Kouri and Mikko Hippeläinen

The high variability in cardiac surgery length – is one of the main challenges for staff managing productivity. This study aims to evaluate the impact of six interventions on…

1053

Abstract

Purpose

The high variability in cardiac surgery length – is one of the main challenges for staff managing productivity. This study aims to evaluate the impact of six interventions on open‐heart surgery operating theatre productivity.

Design/methodology/approach

A discrete operating theatre event simulation model with empirical operation time input data from 2,603 patients is used to evaluate the effect that these process interventions have on the surgery output and overtime work. A linear regression model was used to get operation time forecasts for surgery scheduling while it also could be used to explain operation time.

Findings

A forecasting model based on the linear regression of variables available before the surgery explains 46 per cent operating time variance. The main factors influencing operation length were type of operation, redoing the operation and the head surgeon. Reduction of changeover time between surgeries by inducing anaesthesia outside an operating theatre and by reducing slack time at the end of day after a second surgery have the strongest effects on surgery output and productivity. A more accurate operation time forecast did not have any effect on output, although improved operation time forecast did decrease overtime work.

Research limitations/implications

A reduction in the operation time itself is not studied in this article. However, the forecasting model can also be applied to discover which factors are most significant in explaining variation in the length of open‐heart surgery.

Practical implications

The challenge in scheduling two open‐heart surgeries in one day can be partly resolved by increasing the length of the day, decreasing the time between two surgeries or by improving patient scheduling procedures so that two short surgeries can be paired.

Originality/value

A linear regression model is created in the paper to increase the accuracy of operation time forecasting and to identify factors that have the most influence on operation time. A simulation model is used to analyse the impact of improved surgical length forecasting and five selected process interventions on productivity in cardiac surgery.

Details

International Journal of Health Care Quality Assurance, vol. 20 no. 1
Type: Research Article
ISSN: 0952-6862

Keywords

Article
Publication date: 20 July 2012

Yikun Xie and Qingjin Peng

The purpose of this paper is to present the research for improvement of the operating room in a hospital, to reduce patient waiting time and increase the resource utilization.

2356

Abstract

Purpose

The purpose of this paper is to present the research for improvement of the operating room in a hospital, to reduce patient waiting time and increase the resource utilization.

Design/methodology/approach

Value stream mapping (VSM) is used to represent the entire operating room (OR) process and patient flow to identify problems. Agent‐based simulation (ABS) is applied to model human behaviors in the OR operation. Agents perform human factors in the simulation model with autonomous and interactive functions actively.

Findings

The research outcomes prove the effectiveness of integrated VSM and ABS to improve decision making in human‐centred healthcare environments.

Research limitations/implications

Because the state is dynamically changed, the task priority needs to be updated dynamically. The nurse schedule to transport patients between different units is to be detailed.

Practical implications

Long waiting lists in hospitals lead to patient dissatisfaction and care quality reduction. It is crucial to identify inefficiency and to improve the healthcare delivery effectively.

Originality/value

The paper shows how VSM and ABS are integrated in the modeling for the dynamic OR planning. It improves the simulation modeling of healthcare delivery.

Details

Business Process Management Journal, vol. 18 no. 4
Type: Research Article
ISSN: 1463-7154

Keywords

Article
Publication date: 1 March 1990

James T. Luxhoj and Gene A. Giacomelli

The development of labour standards for the single truss tomatoproduction system is examined. Both time study and predetermined timesystems, such as the Element Times for…

Abstract

The development of labour standards for the single truss tomato production system is examined. Both time study and predetermined time systems, such as the Element Times for Agriculture (ETA) tables and the Maynard Operation Sequence Technique (MOST) tables, are used to determine labour standards for the operations of pruning and harvesting in a single truss tomato production system. The hypothesis is that a predetermined time system could be used to establish greenhouse labour standards, and thus replace the tedious and costly process of direct time study. Such a work measurement system would enable the setting of job standards quickly and accurately. Standardised work models will facilitate cost control of labour operations, and provide data for evaluation of labour costs within future greenhouse system designs. The data indicate that, although the pre‐determined time values varied from measured time study by around 6 per cent to over 23 per cent for pruning, the variation for harvesting ranged approximately from 3 per cent to 7 per cent. The combined results suggest that predetermined time systems can be used effectively to establish greenhouse labour standards for short cycle tasks without the loss of significant accuracy when using an absolute scale.

Details

International Journal of Operations & Production Management, vol. 10 no. 3
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 1 February 2000

Shiu Hong Choi and James Siu Lung Lee

Minimising makespan aims to achieve high utilisation of equipment and resources by getting all jobs out quickly. This is an important scheduling criterion, especially for…

Abstract

Minimising makespan aims to achieve high utilisation of equipment and resources by getting all jobs out quickly. This is an important scheduling criterion, especially for automated systems, because of the high investment cost. The problem, however, becomes complex when many parts and machines are involved. This is because different parts may require different numbers of operations, and there are many possible schedules. For small problems, a mathematical programming model for minimising makespan is formulated. For large problems, a sequencing algorithm based on decomposition and pairwise comparison is proposed. The idea of “total overlapping time” in the sequencing algorithm is introduced to determine the solution of each sub‐schedule. It maximises the number of jobs working at different machines at the same time, while satisfying the parts’ operation precedence and machine constraints. The differences between this method and the traditional graphical method are discussed. The sequencing algorithm significantly reduces the number of schedules for consideration and hence, the computational power required.

Details

Integrated Manufacturing Systems, vol. 11 no. 1
Type: Research Article
ISSN: 0957-6061

Keywords

Article
Publication date: 1 January 2005

Angus Cheung, W.H. Ip, Dawei Lu and C.L. Lai

In this paper, the authors propose the application of an intelligent engine to develop a set of computational schedules for the maintenance of vehicles to cover all scheduled…

2207

Abstract

Purpose

In this paper, the authors propose the application of an intelligent engine to develop a set of computational schedules for the maintenance of vehicles to cover all scheduled flights. The aim of the paper is to maximize the utilization of ground support vehicles and enhance the logistics of aircraft maintenance activities.

Design/methodology/approach

A mathematical model is formulated and the solution is obtained using genetic algorithms (GA). Simulation is used to verify the method using an Excel GA generator. The model is illustrated with a numerical case study, and the experience of this project is summarized.

Findings

The results indicate that this approach provides an effective and efficient schedule for deploying the maintenance equipment resources of the company, China Aircraft Service Limited.

Originality/value

The proposed model using the GA generator provides an effective and efficient schedule for the aircraft maintenance services industry.

Details

Journal of Manufacturing Technology Management, vol. 16 no. 1
Type: Research Article
ISSN: 1741-038X

Keywords

Article
Publication date: 1 July 1989

Biman Das, Alberto Garcia‐Diaz and Clarence L. Hough

For machine‐paced operations a two‐factor monetary incentive planis developed by employing production quantity output and productionwaste as criteria for incentive earnings. The…

Abstract

For machine‐paced operations a two‐factor monetary incentive plan is developed by employing production quantity output and production waste as criteria for incentive earnings. The plan takes into account machine time allowance and increased operator work pace for manual work for establishing standards in a machine‐paced operation. The two incentive earning factors are given proper weights in terms of their relative economic importance. The weights are determined by comparing possible labour and material costs savings when the operators perform at incentive pace level. To demonstrate the working of the proposed monetary incentive plan an illustrative example is presented.

Details

International Journal of Operations & Production Management, vol. 9 no. 7
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 8 January 2018

Chi On Chan and Huay Ling Tay

The purpose of this paper is to highlight the lessons learned from two kaizen events for productivity improvement in a printing company. The paper suggests how to organize lean…

2411

Abstract

Purpose

The purpose of this paper is to highlight the lessons learned from two kaizen events for productivity improvement in a printing company. The paper suggests how to organize lean tools to improve productivity through the use of organized kaizen events in the printing industry to meet defined targets.

Design/methodology/approach

This paper is based on a field study involving participant observations. The relationships among the three specific tools, line balancing, standardized work and standardized layout that are used in a kaizen event of a printing factory, are examined.

Findings

Application of a mix of lean tools resulted in significant productivity improvements of 10-30 percent in the assembly area of the printing company. Based on the outcomes of the lean tools that are applied in various work areas, the best combinations of lean tools are identified and several key considerations are discussed.

Practical implications

This paper shows that a combined set of lean tools such as line balancing, standardized work and standardized layout can be applied to improve productivity in the printing operations, which is identifiable with a mix of processes that are both labor intensive and equipment flexible.

Originality/value

The paper fills the literature gap on the use of specific lean tools: line balancing, standardized work and standardized layout in the printing industry. The findings from this research can be applied to other assembly systems that are similar to the printing industry.

Details

International Journal of Productivity and Performance Management, vol. 67 no. 1
Type: Research Article
ISSN: 1741-0401

Keywords

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