Textos Interpretativos por categorías de análisis

The effective planning and deployment of an organisation’s workforce plays a vital role within service industries. Delivery of services relies primarily on an expensive human workforce which often accounts for a large proportion of overall running costs. Successful

Strategic Planning Tactical Planning Aggregate Planning Operational Planning

What: Location and number of service cen- tres; staff ratios

When: 1-2 years in advance

What: Hiring; training; volume of demand to be met

When: 12-18 months in advance

What: Aggregate allocation of workers’ skills to demand for those skills

When: 1 to 90 days in advance

What: Scheduling and assignment of individ- ual workers to tasks

When: Beginning of week or shift

Figure 4.1.1: Four-stage workforce planning hierarchy for large scale service industries

organisations can establish a competitive edge by carefully planning human resources so that delivery is timely to demand (Owusu and O’Brien, 2013). Indeed, Pokutta and Stauffer (2009) argue that in increasingly competitive markets, this challenge has become paramount for the maximisation of profit and, increasingly, to ensure the survival of organisations.

The importance of workforce planning has garnered considerable academic interest in recent years, being applied to various service industry contexts such as nurse staffing (Brusco and Johns, 1998; Campbell, 1999), call centres (Iravani et al., 2007) and man- ufacturing (Hopp and Van Oyen, 2004; Iravani et al., 2005). A powerful contribution to workforce planning has been the consideration of the skill make-up of the workforce. Cross-training policies have been shown to provide organisations with improved demand coverage via a flexible workforce better placed to cope with variations in demand (Hopp et al., 2004; Inman et al., 2004). Such policies heighten the complexity of the planning task however, bringing about the combinatorial challenge of distributing a workforce over a complex network of skills and varying ability levels.

down into a sequence of interconnected stages of decision making. Figure 4.1.1 presents a planning hierarchy containing three common planning stages: Strategic; Tactical and Operational Planning. Strategic Planning involves the highest level decisions about the scope of the activities of the organisation, typically made years ahead of operations. Tactical Planning describes the actions required to achieve the plans set out in Strate- gic Planning, in this case, the annual or bi-annual setting of required staffing levels and training. The Operational Planning stage is then concerned with the day-to-day scheduling of the resulting workforce and takes as input the configuration of this supply resulting from the previous Tactical Planning stage. Typically, consideration of how a cross-trained workforce’s flexibility can be exploited is left until the final stage when assigning individuals to specific tasks within their skill-set. This assignment problem, as an extension of the NP-hard Generalised Assignment Problem ( ¨Oncan, 2007; Heimerl and Kolisch, 2010), becomes computationally intensive for large workforces however.

An important consideration when planning on such a hierarchy is the effective transi- tion between decisions made at each level. We propose anAggregate Planning stage, po- sitioned at the interface between Tactical and Operational Planning, which contributes to the effective deployment of large workforces with complex cross-training structures. Taking the staffing and training decisions made in Tactical Planning, this stage es- tablishes an effective utilisation of groups of workers’ skills on an aggregate level and quantifies the resulting accumulation of unmet demand (orcarryover) across a planning horizon of a number of weeks. The result is a richer view of demand over the horizon and targets for the time workers spend on each skill upon which effective schedules can be built in the Operational Planning stage.

In service industry contexts in which unmet demand remains in the system, identi- fying future supply and demand imbalances arising from the carryover phenomena is a key issue for planners in this intermediate stage of the planning process. The Aggregate

Planning stage provides several benefits to the organisation in the planning and deliv- ery of services. It allows for a responsive approach well in advance of service delivery; opposed to a reactive approach during the Operational planning phase. By providing a snapshot of the skill utilisation over the planning horizon, the associated inventories required (vehicles, specialist equipment and materials) can be established and put in place. Hence ensuring that vehicles, specialist equipment and materials can be planned for and are in place.

In the case where a portion of demand (such as scheduled maintenance) is pre- planned, there is arguably a degree of flexibility to alter the timing of some service deliveries. For example, if planned work occurs on a day with identified supply shortage, there may be opportunities to advance work to earlier periods with excess supply. This aspect of workforce planning, along with the need to incorporate late running incomplete work in decision making, has received little attention in literature but is of particular relevance to our service industry context. In the literature it is commonly assumed that all demand must be addressed on the day to which it is initially assigned and that any shortfall in supply can be made up with an infinite pool of extra resources (e.g. outsourcing, overtime, etc.) at some additional cost. We contribute to the literature by incorporating the accumulation of unmet demand over the horizon into an Aggregate Planning model which sits prior to the presence of such restrictions on the timing of demand. The proposed model can therefore be used to identify the potential value of temporal demand flexibility, and cross-training as a strategy within this setting, where work can be completed early and be made available for later completion through the carryover of incomplete work across the horizon.

The remainder of the chapter is as follows. In Section 4.2 we provide a literature review of the workforce planning process, with a particular focus on service industries and the operational challenges faced. We discuss the key components of an aggregate

cross-trained workforce planning model with temporal demand flexibility in Section 4.3, concluding discussion with the model itself. The model’s performance and the impli- cations of solutions for planners are explored for an industry motivated case study in Section 4.4. This is extended to a broader numerical study exploring how performance is affected by various supply and demand characteristics in Section 4.5. Finally, conclu- sions and extensions are discussed in Section 4.6.