Workforce scheduling and planning : a combinatorial approach

This thesis investigates solution methodologies for concrete combinatorial problems in scheduling and planning. In all considered problems, it is assumed that the available information does not change over time; hence these problems have a deterministic structure. The problems studied in this thesis are divided into two groups; \workforce scheduling" and \planning". In workforce scheduling, the center problem is to build a schedule of tasks and technicians. It is assumed that the time line is split into workdays. In every workday, tasks must be grouped as sequences, each being performed by a team of technicians. Skill requirements of every task in a sequence must be met by the assigned team. This scheduling problem with some other aspects is di??cult to solve quickly and e??ciently. We developed a Mixed Integer Programming (MIP) based heuristic approach to tackle this complex scheduling problem. Our MIP model is basically a formulation of the matching problem on bipartite graphs and it enabled us to have a global way of assigning technicians to tasks. It is capable of revising technician-task allocations and performs very well, especially in the case of rare skills. A workday schedule of the aforementioned problem includes many-to-one type workforce assignments. As the second problem in workforce scheduling, stability of these workforce assignments is investigated. The stability de??nition of Gale-Shapley on the Marriage model is extended to the setting of multi-skill workforce assignments. It is shown that ??nding stable assignments is NP-hard. In some special cases stable assignments can be constructed in polynomial time. For the general case, we give linear inequalities of binary variables that describe the set of stable assignments. We propose a MIP model including these linear inequalities. To the best of our knowledge, the Gale-Shapley stability is not studied under the multi-skill workforce scheduling framework so far in the literature. The closed form description of stable assignments is also the ??rst embedding of the Gale-Shapley stability concept into an NP-complete problem. In the second problem group, two vehicle related problems are studied; the "dial a ride problem" and the "vehicle refueling problem". In the former, the goal is to check whether a list of pick-up and delivery tasks can be achieved under several timing constraints. It is shown this feasibility testing can be done in linear time using interval graphs. In the vehicle refueling problem, the goal is to make refueling decisions to reach a destination such that the cost of the travel is minimized. A greedy algorithm is presented to ??nd optimal refueling decisions. Moreover, it is shown that the vehicle refueling problem is equivalent to a ow problem on a special network

Job Mix, Performance Pay, and Matching Outcomes: Contracting with Multiple Heterogeneous Agents

We examine the problem of designing performance contracts with multiple agents when principals must compete for quality teams from a heterogeneous pool of agents. The trade-off principals face between good recruiting and good team performance provides micro foundations for agents to form stable matches, and for initially identical principals to adopt different organizational schemes. The equilibrium pattern of team formation exhibits two distinct, and inversely related, forms of assortative matching. We find that a greater share of principals offering diverse performance incentives across teammates (extensive margin), leads to a lesser degree of heterogeneity in abilities within teams on average (intensive margin). We apply the model to firm behavior to examine the mix of jobs offered and the degree of performance pay in a general equilibrium environment. At the aggregate level, increases in the supply of high-skilled workers leads to a polarization of jobs offered, i.e. relatively greater use of high- and low- skill occupations, consistent with changing labor demands in recent history. Moreover, skill accumulation among the labor force induces more firms to offer a steep set of performance contracts.Multi-Agent Contracting, Matching, Job Design

Workplace 2000: A Delphi-Study

[Excerpt] Prognosticate and one thing is certain: you are likely to be wrong. Then why speculate about Workplace 20001 Because Boulding is right; as the future unfolds, surprise is preferable to astonishment. Informed speculation enhances anticipation and understanding, the bases of informed decision-making. It produces a vision with which to agree or disagree, and the means to ascertain why. If the vision proves disagreeable, there is a baseline from which to plot a preferred scenario. For in the end, Workplace 2000 will emerge not from prediction, but from choice

Trade unions and collective bargaining

The authors assert that changing world markets and new technologies are driving industrial restructuring. The ability of developing countries and the new transitional economies to compete in the global marketplace will depend on their ability to transform industrial relations policies involving trade unions and collective bargaining so that they promote flexibility in the workplace and encourage the formation and effective use of human resources. History has shown, they say, that there are certain key moments of transition in industrial relations systems. After that time, systems get set and are hard to modify. Often these key moments are the result of legislative changes (such as the National Labor Relations Act and the emergence of public sector unions after the burgeoning of public sector legislation in the United States). Sometimes they are the result of key historical or economic junctures (such as the postwar reconstruction in Japan and Germany, and independence movements in the developing world). Recent pressures for structural change in the developing world present an opportunity for major transitions in industrial relations. Drawing on the Japanese and German experiences, as well as experiences in the developing world, the authors focus on lessons that can be applied in guiding this transformation. Workers participation in decisionmaking, they contend, is critical for bringing about the essential popular acceptance of changes that will come with industrial restructuring. It is also important to coordinate and integrate industrial relations policy with other social, legal, economic, and educational policies. The education system, for example, should not be overproducing college graduates when there is an undersupply of unskilled and skilled workers.Labor Management and Relations,Environmental Economics&Policies,Labor Standards,Politics and Government,Work&Working Conditions

The shift team formation problem in multi-shift manufacturing operations

This paper addresses the problem of assigning operators to teams that work in single-, two-, or three-day shift systems. The problem was motivated by, and illustrated with a case situation encountered in Dutch manufacturing industry. The problem addressed forms an extension of cell formation problems which are currently in the phase of addressing labor-related issues in cell design. A generalized goal problem formulation is presented to address multiple, conflicting objectives covering cross-training of workers, ensuring adequate levels of labor flexibility and minimizing labor-related costs. The proposed solution procedure consists of two phases. In the first phase, shift systems, in which applicable machines and the sizes of each shift team are identified. The next phase deals with assignment of operators to various teams and identification of specific cross-training needs for various workers. This phase involves the use of interactive goal programming. The methodology is illustrated by details from the case situation as well as a numerical example.

Skill Acquisition, Incentive Contracts and Jobs: Labor Market Adjustment to Trade

This paper examines how global integration influences worker behavior regarding skill acquisition, as well as firm behavior regarding incentive contracts and occupational diversity. The approach integrates several key components of international trade and the wage distribution in developed countries: namely heterogeneous firms, trade in similar goods, and performance payments to workers that endogenously obtain different skill levels. Greater trading opportunities reduce aggregate prices, causing workers to experience a greater marginal utility derived from income, as well as the skills that aid them in fulfilling performance contracts. Firms respond to skill accumulation among the labor force by adjusting the provision of incentive contracts, and the types of jobs they offer. Labor market adjustment to trade liberalization is characterized by a more steep, but less extensive, provision of incentive contracts among the labor force; higher overall wage inequality exhibiting a U-shaped differential; and job polarization across skill-groups.Job Polarization, Performance Pay, Trade Adjustment

Short-term manpower management in manufacturing systems: new requirements and DSS prototyping

The short-term planning and scheduling of discrete manufacturing systems has mostly focused in the past on the management of machines, implicitly considered as the critical resources of the workshops. Some of the present schedulers claim to also manage human resources, but perform most of the time a local allocation of operators to machines, these operators having regular working hours. However, it seems clear that the workforce has a specificity that should be better taken into account by short-term planning facilities. Moreover, the variability of the weekly working hours through the year will shortly become a rule and not anymore an exception. On the base of a questionnaire answered by 19 French companies of different sizes and industrial sectors, we have tried to identify more precisely some industrial requirements concerning the short-term management of human resources. The growing interest in annualised hours together with the lack of software tools that allow to implement it practically is one of the results of this questionnaire. We suggest in this article the specification of a decision support system for short-term manpower management under annualised hours, taking into account the competence of the operators. A software prototype has been developed according to these specifications; the results of a simple but representative example are described

Agency working in Britain: character, consequences and regulation

Debate over the nature of temporary agency work has intensified in recent times, spurred on by a proposed European directive and by speculation about links with the much heralded ‘knowledge’ economy. This paper examines the debate, focusing on the current character of agency work in Britain. Using data from the Labour Force Survey, we assess some of the claims commonly made about agency work, relating to the personal and employment characteristics of those engaged in such work, the motives of agency workers and the prospects for those who take up agency jobs. In considering the arguments surrounding regulatory change, we find there is a strong case for regulation, but that this rests on the continued disadvantage associated with agency work, with little evidence of an impact from the purported ‘knowledge’ economy.