برنامه ریزی کارکنان در صنایع خدماتی با در دسترس بودن و تقاضای کارکنان انعطاف پذیر  Employee Scheduling in Service Industries with Flexible Employee Availability and Demand

1 Introduction Efficient management of workforce is one of the most important concerns in both manufacturing and service organizations, since it has a direct effect on the productivity of day-to-day operations and the quality of the service provided. Especially the employee scheduling problem has attracted considerable amount of research due to high costs associated with employee utilization. Employee scheduling problem is NP-Hard (Garey and Johnson, 1979), and this, by itself, indicates a major challenge. However, in addition to this major challenge, concerns like large number of strict rules and regulations set by governments and labor unions, which impose hard constraints over the feasible utilization of employees, and non-numerical objectives such as well-being and happiness of the employees, and fairness between employees makes the problem even more interesting as a research topic. In this study, we investigate an employee scheduling problem that we frequently face in a group of special health-care organizations, such as care centers for children with disabilities and nursing homes for elderly. Operating environment of these special organizations involves two basic forms of flexibility. The first flexibility is in the demand for services rendered in these organizations. The types of patients served require special personalized care. Timing, content and length of services vary significantly, and it is virtually impossible to generate a balanced pattern of services for a prolonged period of time. Services such as emergency health-care, social events, and educational activities that need case specific resources (personnel and equipment) in an irregular manner must be provided regularly. The second flexibility is in the availability of human resources that is utilized in the delivery of these highly flexible services. The span of skills required is very large, and consequently, it is almost impossible to have full time contracts with all the required human personnel. Hence, these health-care organizations need to provide a set of flexible services using employees with flexible contracts in addition to regular full time employees. The necessity of providing service with flexible contracts is in-line with the general trend of increasing flexible working conditions in industrialized countries. In recent years, most European countries have installed new legislations to enable employees to request flexible working conditions, including contractual, spatial and temporal flexibility (Joyce et al., 2010). In terms of employee scheduling, flexible working contracts make it unnecessary to define a relatively fixed work management structure like a shift. In a flexible organization, the main management concern is not to manage the existence of the employee in a fixed location, but to dynamically manage the match between the availability of the employees with the service requirements.