Search

A practical nurse rostering problem of an Italian hospital is considered. The nurse rostering is required to generate the nursing staff shifts subject to various operational and contractual requirements.

A superior lower bound on the basis of the Lagrangean relaxation procedure, along with two new control conditions are suggested for the solution of the two machine total finishing period flow shop problem. A branch-and-bound algorithm, in which the bound and conditions are fixed together, is found to provide the best solution for problems of average magnitude.

The NP-hard scheduling problem of minimizing total completion time in a two-machine flow shop is examined. Five known lower bounds and two new ones are shown. Various versions of a branch and bound method are developed by using, both individually and combined, these lower bounds. A heuristic process which employs a constructive O(n squared) time method, which calculates a good starting solution and a neighborhood search based on pairwise interchanges, is shown.

The problem of scheduling Compal S.A.'s production of perishable goods is examined. Since the problem's objective functions are conflicting and the commodity is subject to seasonal demand, it is decomposed into two sub-problems, namely, annual planning and short-term scheduling. For these, linear programming and integer programming models are derived, respectively, and a two-stage heuristic is developed.

A study was conducted to examine a proposal of the design for a cellular structure to solve the planning and control problem. The study applies objective oriented methods for the problem's specification and design. The proposal is then applied to flow-shop and job scheduling problems involving various numbers of lots and machines. Results show that the proposed model exhibits potential solutions following those of existing heuristic and exact techniques.

A practical problem encountered by the management of a tennis club is the organization of a tennis tournament for the club members. The tournament participants are split into different series: in each series, every player plays once a week with a different opponent in a round robin tournament. All matches are subject to a time limit corresponding to one hour. All the series share the same pool of courts, whose weekly availability is predefined. In addition, the players have their own availability constraints. Given the courts and players availability, the objective is to schedule the tournament with no violation of the constraints or, more realistically, in order to maximize the number of feasible matches. This problem can be formulated as a maximum matching problem, with the additional constraint that each player must play just once a week. It can also be modeled as a maximum clique problem. A two-step heuristic procedure is proposed to solve the problem: first, the round robin tournaments of each series are generated, then the matches of each tournament are assigned to the available courts for every week by means of a local search procedure. The procedure has been succesfully implemented and is currently used by the tennis club. [ABSTRACT FROM AUTHOR]