Real-time schedule adjustment decisions: a case study

Service capacity management has been extensively studied and successfully applied in many industries, with an emphasis on tour/shift scheduling and assignment decisions. However, few studies have addressed real-time work schedule adjustment decisions made necessary by demand uncertainty and/or labor supply disruption. This case study deals with the real-time work schedule adjustment decision and investigates the association of managerial experience, workforce mix (full- and part-time staff), and information accuracy with managers’ adjustment decisions. We designed an experiment that involved practicing service managers from a McDonald's franchise who provided their adjustment decisions for a given set of test scenarios. Their decisions were analyzed and evaluated via a controlled experiment. Using profitability as the primary performance measure, the study identifies the following outcomes: First, senior managers of a store with a higher proportion of part-time staff made more adjustments and attained slightly higher profitability than junior managers, when all employees accepted adjusted schedules. Second, managers of a store with a higher proportion of part-time staff were able to make slightly higher profits, particularly when capacity shortages occurred. And third, to achieve the majority of the benefits from schedule adjustments, it is sufficient to search for information that correctly identifies the direction of demand changes, rather than identifying the exact magnitude of the changes.     

Cross‐Training with Imperfect Training Schemes

Cross‐training workers is one of the most efficient ways of achieving flexibility in manufacturing and service systems for increasing responsiveness to demand variability. However, it is generally the case that cross‐trained employees are not as productive on a specific task as employees who were originally trained for that task. Also, the productivity of the cross‐trained workers depends on when they are cross‐trained. In this work, we consider a two‐stage model to analyze the effects of variations in productivity levels on cross‐training policies. We define a new metric called achievable capacity and show that it plays a key role in determining the structure of the problem. If cross‐training can be done in a consistent manner, the achievable capacity is not affected when the training is done, which implies that the cross‐training decisions are independent of the opportunity cost of lost demand and are based on a trade‐off between cross‐training costs at different times. When the productivities of workers trained at different times differ, there is a three‐way trade‐off between cross‐training costs at different times and the opportunity cost of lost demand due to lost achievable capacity. We analyze the effects of variability and show that if the productivity levels of workers trained at different times are consistent, the decision maker is inclined to defer the cross‐training decisions as the variability of demand or productivity levels increases. However, when the productivities of workers trained at different times differ, an increase in the variability may make investing more in cross‐training earlier more preferable.     

Staffing a Multiskilled Workforce with Varying Levels of Productivity: An Analysis of Cross-training Policies*

Service operations that utilize cross-trained employees face complex workforce staffing decisions that have important implications for both cost and productivity. These decisions are further complicated when cross-trained employees have different productivity levels in multiple work activity categories. A method for policy analysis in such environments can be beneficial in determining low-cost staffing plans with appropriate cross-training configurations. In this paper, we present an integer linear programming model for evaluating cross-training configurations at the policy level. The objective of the model is to minimize workforce staffing costs subject to the satisfaction of minimum labor requirements across a planning horizon of a single work shift. The model was used to evaluate eight cross-training structures (consisting of 36 unique cross-training configurations) across 512 labor requirement patterns. These structures, as well as the labor requirement patterns, were established based on data collected from maintenance operations at a large paper mill in the United States. The results indicate that asymmetric cross-training structures that permit chaining of employee skill classes across work activity categories are particularly useful.     

Impacts of demand and supply factors on the capacity scheduling performance of logistics service supply chain with mass customisation service modes: an empirical study from China

This paper studies the influence of the demand–supply environment on the capacity scheduling performance of the logistics service supply chain. According to the key characteristics of the demand–supply environment, the cases of five Chinese companies were introduced and cross-analysed, then research hypotheses were developed. After receiving 154 valid questionnaires and testing our hypotheses, some key conclusions were obtained. From the aspect of demand, there is a positive correlation between the customised levels of demand and the scheduling cost of logistics service integrators but a negative correlation between the customised levels of demand and the scheduling flexibility; From the aspect of supply, a higher self-support ratio of logistics source and a higher sourcing integrity of logistics service integrators will lead to a higher scheduling cost and a lower scheduling flexibility; a whole-process performance evaluation is a moderator, which will positively improve the impact of the whole process scheduling performance.     

Schedule Recovery: Unplanned Absences in Service Operations*

The U.S. service sector loses 2.3% of all scheduled labor hours to unplanned absences, but in some industries, the total cost of unplanned absences approaches 20% of payroll expense. The principal reasons for unscheduled absences (personal illness and family issues) are unlikely to abate anytime soon. Despite this, most labor scheduling systems continue to assume perfect attendance. This oversight masks an important but rarely addressed issue in services management: how to recover from short‐notice, short‐term reductions in planned capacity. In this article, we model optimal responses to unplanned employee absences in multi‐server queueing systems that provide discrete, pay‐per‐use services for impatient customers. Our goal is to assess the performance of alternate absence recovery strategies under various staffing and scheduling regimes. We accomplish this by first developing optimal labor schedules for hypothetical service environments with unreliable workers. We then simulate unplanned employee absences, apply an absence recovery model, and compute system profits. Our absence recovery model utilizes recovery strategies such as holdover overtime, call‐ins, and temporary workers. We find that holdover overtime is an effective absence recovery strategy provided sufficient reserve capacity (maximum allowable work hours minus scheduled hours) exists. Otherwise, less precise and more costly absence recovery methods such as call‐ins and temporary help service workers may be needed. We also find that choices for initial staffing and scheduling policies, such as planned overtime and absence anticipation, significantly influence the likelihood of successful absence recovery. To predict the effectiveness of absence recovery policies under alternate staffing/scheduling strategies and operating environments, we propose an index based on initial capacity reserves.     

Equivalent Alternate Solutions for the Tour Scheduling Problem*

Achieving minimum staffing costs, maximum employee satisfaction with their assigned schedules, and acceptable levels of service are important but potentially conflicting objectives when scheduling service employees. Existing employee scheduling models, such as tour scheduling or general employee scheduling, address at most two of these criteria. This paper describes a heuristic to improve tour scheduling solutions provided by other procedures, and generate a set of equivalent cost feasible alternatives. These alternatives allow managers to identify solutions with attractive secondary characteristics, such as overall employee satisfaction with their assigned tours or consistent employee workloads and customer response times. Tests with both full-time and mixed work force problems reveal the method improves most nonoptimal initial heuristic solutions. Many of the alternatives generated had more even distributions of surplus staff than the initial solutions, yielding more consistent customer response times and employee workloads. The likelihood of satisfying employee scheduling preferences may also be increased since each alternative provides a different deployment of employees among the available schedules.     

Labor Utilization Effects of Labor Scheduling Flexibility Alternatives in a Tour Scheduling Environment

This study used a factorial experimental design and a new modeling methodology to investigate the impact of a number of labor scheduling flexibility alternatives and labor requirements characteristics on labor utilization within a tour scheduling environment. Break-placement flexibility and shift-length flexibility were found to be extremely effective in improving labor utilization for all labor requirement distributions used. Flexibility with respect to the number of days included in a tour schedule resulted in substantial improvement in labor utilization for all labor requirements distributions exhibiting daily and/or weekly variation. Surprisingly, virtually no improvement in labor utilization was achieved for any labor requirement distribution by the removal of requirements for consecutive days off. In addition, almost no improvement was found by allowing the shift start time to vary across the working days included in tours. High labor requirement amplitude was found to have a strong adverse effect on labor utilization while longer operational days were associated with improved labor utilization for all labor requirement distributions. We discuss the implications of these results for service operations management and provide suggestions for future research.     

Atypical Employment Relations and Government Policy in Europe

Abstract. This paper analyses government policy towards the two major forms of atypical work in Europe: part-time employment and temporary work. It is submitted that the policies implemented promote the volume of marginal part-time employment and temporary work. The policies aiming at more temporary jobs did not result in additional employment; they merely resulted in a redistribution of unemployment and a shift in the recruitment patterns in the direction of subsidised temporary jobs. Too much emphasis on numerical flexibility is not without danger. Countries run the risk that employers will not pay sufficient attention to the source of their long-term flexibility, manpower training. I t is argued that regular part-time work is an alternative for uncertain temporary jobs, Its potential expansion is considerable. Some recommendations are put forward to promote regular part-time jobs and improve the position of flexible part-time workers and temporary workers.     

Part-Time Work in the EEC Countries: Evolution during the 1980s

Whereas part-time working remains the exponent par excellence of the flexibility of female employment, its relative growth seems to have come to a standstill in both Denmark and the United Kingdom as far as women are concerned, and for men it is now becoming more a matter of young people offsetting studies and work. In France, the Netherlands, Belgium, the UK, Ireland and Germany, the increase in female employment between 1983 and 1989 is largely attributable to the growth of part-time employment. The difference with respect to the countries of the South of Europe is striking since the proportion of part-time working there is low, and has not increased significantly since 1983. Its concentration in already very close sectors, its non-optional nature, insecurity and awkward working hours make part-time employment of very little personal value for employees.     

Home healthcare integrated staffing and scheduling

Workforce planning for home healthcare represents an important and challenging task involving complex factors associated with labor regulations, caregivers’ preferences, and demand uncertainties. This task is done manually by most home care agencies, resulting in long planning times and suboptimal decisions that usually fail to meet the health needs of the population, to minimize operating costs, and to retain current caregivers. Motivated by these challenges, we present a two-stage stochastic programming model for employee staffing and scheduling in home healthcare. In this model, first-stage decisions correspond to the staffing and scheduling of caregivers in geographic districts. Second-stage decisions are related to the temporary reallocation of caregivers to neighboring districts, to contact caregivers to work on a day-off, and to allow under- and over-covering of demand. The proposed model is tested on real-world instances, where we evaluate the impact on costs, caregiver utilization, and service level by using different recourse actions. Results show that when compared with a deterministic model, the two-stage stochastic model leads to significant cost savings as staff dimensioning and scheduling decisions are more robust to accommodate changes in demand. Moreover, these results suggest that flexibility in terms of use of recourse actions is highly valuable as it helps to further improve costs, service level, and caregiver utilization.     

Flexibility Structure and Capacity Design with Human Resource Considerations

Most service systems consist of multidepartmental structures with multiskill agents that can deal with several types of service requests. The design of flexibility in terms of agents' skill sets and assignments of requests is a critical issue for such systems. The objective of this study was to identify preferred flexibility structures when demand is random and capacity is finite. We compare structures recommended by the flexibility literature to structures we observe in practice within call centers. To enable a comparison of flexibility structures under optimal capacity, the capacity optimization problem for this setting is formulated as a two‐stage stochastic optimization problem. A simulation‐based optimization procedure for this problem using sample‐path gradient estimation is proposed and tested, and used in the subsequent comparison of the flexibility structures being studied. The analysis illustrates under what conditions on demand, cost, and human resource considerations, the structures found in practice are preferred.     

On‐Call Overtime for Service Workforce Scheduling when Demand Is Uncertain

This article builds on prior research to develop shift scheduling models that include on‐call overtime for service environments where demand is uncertain. The research is motivated by recent developments in nurse scheduling, such as laws prohibiting mandatory overtime and the popularity of self‐scheduling systems. For single‐period scenarios, models are developed, solution methods are described, and results are explored for a variety of environments. Results show that the use of on‐call overtime can reduce costs slightly, with the amount of savings dependent on characteristics of the scheduling environment. The factor that most significantly affects cost savings is the cost of outside agency workers relative to overtime workers. In addition to lowering costs, on‐call overtime greatly reduces reliance on outside agency workers, which can have important practical implications in terms of quality of service and workforce morale. Results based on single‐period models motivate multiperiod formulations for single‐ and multidepartment scenarios, and solution methods are outlined for those cases. The possibility of using multiperiod models within a rolling horizon framework with forecast updating is discussed. This goes along with an extension of the traditional workforce management hierarchy that separates overtime and regular‐time scheduling, as seen in practice with self‐scheduling and shift‐bidding systems.     

Improving the Utilization of Front-Line Service Delivery System Personnel*

There are two types of work typically performed in services which differ in the degree of control management has over when the work must be done. Serving customers, an activity that can occur only when customers are in the system is, by its nature, uncontrollable work. In contrast, the execution of controllable work does not require the presence of customers, and is work over which management has some degree of temporal control. This paper presents two integer programming models for optimally scheduling controllable work simultaneously with shifts. One model explicitly defines variables for the times at which controllable work may be started, while the other uses implicit modeling to reduce the number of variables. In an initial experiment of 864 test problems, the latter model yielded optimal solutions in approximately 81 percent of the time required by the former model. To evaluate the impact on customer service of having front-line employees perform controllable work, a second experiment was conducted simulating 5, 832 service delivery systems. The results show that controllable work offers a useful means of improving labor utilization. Perhaps more important, it was found that having front-line employees perform controllable work did not degrade the desired level of customer service.     

IMPLICIT OPTIMAL AND HEURISTIC LABOR STAFFING IN A MULTIOBJECTIVE,MULTILOCATION ENVIRONMENT*

This paper presents a tractable set of integer programming models for the days-off scheduling of a mix of full- and part-time employees working α to β days/week (cycle) in a multiple-objective, multiple-location environment. Previous models were formulated to specifically schedule part-time employees working either two or three days per week. These models were intractable because they required complete employee schedule information. The new models are deemed implicit optimal since they are required to supply only essential information. While the number of variables in previous models is an exponential increasing function of β-α, the size of three of the new models is independent of α and β. The first three models developed here (as in [18]) deal with the trade-offs between idle time, the number of employees required to work at multiple “locations,” and the size of the total labor pool. The inherent flexibility of the implicit modeling approach is illustrated by the presentation of various modifications of the basic models. These modifications permit the use of preference weights on the number of employee work days/week (cycle) or the minimization of payroll costs where differential pay rates exist. These latter models may also be formulated such that idle time is ignored, constrained or minimized. The execution time for the implicit models (on a CDC CYBER 730 computer with commercially available software) averaged well under five seconds on 1200 trial problems for the type of application considered in [18]. A solution was obtained in less than 46 seconds of CPU time for a trial problem which would have required over 1.4 million integer variables with previous models. The availability of optimal solutions was invaluable in the development of two heuristics designed to deal with the trade-offs of [16]. In an experimental analysis a previous heuristic produced results which averaged from 74 to 508 percent above optimum across six experimental conditions. The comparable new heuristic produced results which averaged from 3 to 8 percent above optimum for the same experimental conditions. The paper concludes by developing a framework to integrate the results of this research with the tour scheduling problem and by identifying several other areas for related research.     

‘Quality’ part-time work in Australian organizations: implications for HRD

Part-time work is an international phenomenon. Many western countries show similar patterns to Australia, with a significant increase in part-time work in the last twenty to twenty-five years. In Australia, part-time work has developed some unique features, particularly as it often involves lower wages and poor conditions. Part-time employees in Australia are often excluded from human resource development (HRD) activities such as training and career tracks provided to full-time workers. The experience of particular Australian organizations illustrates possible avenues for quality part-time work. This paper examines practical examples of quality part-time work in eight Australian organizations across five industries (nursing, hospitality, retail, local government and the legal profession). Using case study research, the paper discusses the dimensions of quality part-time work in different industry and occupational contexts from an HRD perspective.     

Shop Floor Control When Tacit Worker Knowledge is Important

We investigate a shop where the workers and supervisors have tacit knowledge of how to operate efficiently and where efficiency is important to providing capacity to meet demand. This tacit knowledge includes setup dependencies between products as well as which worker or machine is best suited for a particular product. We discuss a real‐world shop where this is the case. Management expects workers and supervisors to use their knowledge to schedule efficiently by monitoring their performance based on standards. The question that we explore is how management should control for due date performance in light of the discretion given to the workers and supervisors to sequence jobs on the basis of efficiency. We explore management control of due date performance through the use of order review and release (ORR) and management expediting. We find that although ORR is quite effective at reducing work‐in‐process (WIP) inventories, it may foster very late deliveries in a shop such as this. In fact, under such conditions, deftly executed expediting with no ORR at all can be far more effective at supporting all deliveries. Even improving ORR into a hybrid by actively updating path efficiencies (observed from supervisor/worker scheduling) did not support a change to this conclusion. Conversely, when conditions are created where tacit knowledge plays a reduced role or utilization is decreased, ORR delivers in a timely manner. The interaction between utilization, WIP levels, and worker knowledge all help dictate the appropriate control methodology.     

Increasing flexibility in shiftwork arrangements

Renewed interest in increasing flexibility in working time arrangements derives from both social and economic changes. The dominant reasons for greater flexibility in shiftwork arrangements relate to diverse business demands resulting from competitive pressures and rapid technological change, modern workers' personal preferences about the timing of work, and the reduction in hours of work. Many new patterns are applied to meet these demands. A review of innovative patterns reveals their close link with shorter working hours and diversifying career needs. Typical patterns include (a) hours averaging schemes, (b) flexible daily hours, (c) individualized free time schemes. (d) flexitime plus shift systems, (e) a combination of full-time and part-time systems, (f) job sharing, (g) temporary transfer to day work, and (h) career break schemes. Attention is drawn to multi-skilling of workers associated with more independent responsibility and closer communication. Changes to a flexible pattern are usually a result of consultations that respond to the conflicting interests of employers and workers. Support is necessary for a process of informed joint planning. Particularly useful are: (1) identification of operational demands and individual preferences about increasing flexibility in work schedules; (2) presentation of available options with information on implications for workers' health and social life; and (3) facilitating training and group consultation. The adjustments required depend greatly on how the tasks of individual workers are reorganized. In increasing the flexibility of shift schedules, it is important to learn from positive experiences of joint optimization of work content and working time arrangements.     

Increasing flexibility in shiftwork arrangements

Abstract

Renewed interest in increasing flexibility in working time arrangements derives from both social and economic changes. The dominant reasons for greater flexibility in shiftwork arrangements relate to diverse business demands resulting from competitive pressures and rapid technological change, modern workers' personal preferences about the timing of work, and the reduction in hours of work. Many new patterns are applied to meet these demands. A review of innovative patterns reveals their close link with shorter working hours and diversifying career needs. Typical patterns include (a) hours averaging schemes, (b) flexible daily hours, (c) individualized free time schemes. (d) flexitime plus shift systems, (e) a combination of full-time and part-time systems, (f) job sharing, (g) temporary transfer to day work, and (h) career break schemes. Attention is drawn to multi-skilling of workers associated with more independent responsibility and closer communication. Changes to a flexible pattern are usually a result of consultations that respond to the conflicting interests of employers and workers. Support is necessary for a process of informed joint planning. Particularly useful are: (1) identification of operational demands and individual preferences about increasing flexibility in work schedules; (2) presentation of available options with information on implications for workers' health and social life; and (3) facilitating training and group consultation. The adjustments required depend greatly on how the tasks of individual workers are reorganized. In increasing the flexibility of shift schedules, it is important to learn from positive experiences of joint optimization of work content and working time arrangements.     

Service Completion Estimates for Cross‐trained Workforce Schedules under Uncertain Attendance and Demand

Although cross‐trained workers offer numerous operational advantages for extended‐hour service businesses, they must first be scheduled for duty. The outcome from those decisions, usually made a week or more in advance, varies with realized service demand, worker attendance, and the way available cross‐trained workers are deployed once the demands for service are known. By ignoring the joint variability of attendance and demand, we show that existing workforce scheduling models tend to overstate expected schedule performance and systematically undervalue the benefits of cross‐training. We propose a two‐stage stochastic program for profit‐oriented cross‐trained workforce scheduling and allocation decisions that is driven by service completion estimates obtained from the convolution of the employee attendance and service demand distributions. Those estimates, reflecting optimal worker allocation decisions over all plausible realizations of attendance and demand, provide the gradient information used to guide workforce scheduling decisions. Comparing the performance of workforce scheduling decisions for hundreds of different hypothetical service environments, we find that solutions based on convolution estimates are more profitable, favor proportionately more cross‐trained workers and fewer specialists, and tend to recommend significantly larger (smaller) staffing levels for services under high (low) contribution margins than workforce schedules developed with independent expectations of attendance and demand.     

Skill utilization and well-being: a cross-level story of day-to-day fluctuations and personal intrinsic values

The opportunity to use one's skills at work is an important prerequisite for employee well-being. Drawing on self-determination and person-environment fit theory, this diary study aims to add to our understanding of this important phenomenon in two ways. Firstly, we examine the associations of within-subject daily variations in skill utilization with well-being. Secondly, we model work value orientation as a between-subject factor that moderates this within-subject relationship. Specifically, we advocate that daily skill utilization is more beneficial (in terms of more daily work engagement and less daily emotional exhaustion) for employees holding predominantly intrinsic (i.e. self-development, community contribution) as opposed to extrinsic (i.e. financial success, status) values. Results of multilevel modelling using diary data from 99 service workers over five working days, supported the assumption that daily skill utilization was positively related to daily work engagement, particularly among employees holding a predominantly intrinsic work value orientation. Contrary to our expectations, daily skill utilization was unrelated to daily exhaustion, both for employees holding high and low intrinsic values. The discussion highlights the importance of, and employees’ receptiveness to, variations in beneficial working conditions.