Mark McKnew - Academia.edu (original) (raw)

Papers by Mark McKnew

Proceedings of the 24th conference on Winter simulation - WSC '92, 1992

Cornell Hotel and Restaurant Administration Quarterly, 1997

How can one buffet turn its tables in 40 minutes, while another needs go? A computer model can sh... more How can one buffet turn its tables in 40 minutes, while another needs go? A computer model can show where the holdups are and evaluate potential changes.

This article presents a unique heuristic model for purchased item lot-sizing. The model subsequen... more This article presents a unique heuristic model for purchased item lot-sizing. The model subsequently is tested using 20 historically popular sample problems. The development of heuristic lot-sizing models was initiated as a result of difficulties identified during evaluation of the multi-level lot-sizing problem encountered in using material requirements planning systems. The "technique for order placement and sizing" (TOPS) is based on the logic of the "incremental part-period algorithm," and incorporates four distinct phases. It compares incremental costs and benefits of revising an initial order release schedule by inserting new orders or shifting existing ones. Results of an experimental process exhibited single-line optimal solutions for all test cases. Additionally, execution times were similar to much simpler but less accurate techniques than those of the optimizing Wagner-Whitin routine.

Socio-Economic Planning Sciences, 1989

A simpIe regression model is developed to estimate the number of servers necessary to cover a reg... more A simpIe regression model is developed to estimate the number of servers necessary to cover a region, Data for the model were obtained within a research design that inciuded five replications of 180 experimental conditions. A total of 300 rectangular regions were generated, and a set covering location problem was solved for each region using three distance metrics. Statistical resuits established coverage radius, compactness, and the number of nodes in the region to be significant factors. The resulting regression model was applied to a South Carolina county. Its estimates are seen to be very close to the number of units needed to cover. The model is shown to be a convenient technique for quickly estimating the number of servers while exhibiting an error distribution that is conservatively biased towards overestimation.

Socio-Economic Planning Sciences, 1992

An application of a spatially distributed queuing model to an ambulance system is presented. The ... more An application of a spatially distributed queuing model to an ambulance system is presented. The purpose of this research was to assess the usefulness of a variation of the "hypercube" queuing model developed specifically for modeling an ambulance system. The model was applied to the emergency medical system of Greenville County, South Carolina using historical data. Results indicate that the model provides reasonably accurate estimates of system performance measures when the input parameters can be accurately specified.

Socio-Economic Planning Sciences, 1993

This research develops a workload balancing model that incorporates a preference list for a fixed... more This research develops a workload balancing model that incorporates a preference list for a fixed number of ambulance stations and simple concepts of queuing theory into a mathematical programming formulation. The workload balancing model is demonstrated on actual operating data from the Emergency Medical Service (EMS) system of Shanghai, P.R. China. Results indicate that the model is able to minimize the workload Imbalance among existing stations by assigning ambulance units on the basis of demand received by each station.

SIMULATION, 1994

Abstract This paper addresses the problem of modeling time-varied arrival rates in gicetcing syst... more Abstract This paper addresses the problem of modeling time-varied arrival rates in gicetcing systems. The approach is to break down a 24-hour period into small time durations such that an average arrival rate during the time duration can be reasonably viewed as constant. ...

Management Science, 1982

Page 1. MANAGEMENT SCIENCE Vol. 28, No. 7, July 1982 Printed in? USA POLICE PATROL-INITIATED ACTI... more Page 1. MANAGEMENT SCIENCE Vol. 28, No. 7, July 1982 Printed in? USA POLICE PATROL-INITIATED ACTIVITIES WITHIN A SYSTEMS QUEUEING MODEL* RICHARD C. LARSONt AND MARK A. McKNEW$ Officers in ...

The Journal of Trauma: Injury, Infection, and Critical Care, 1986

The Journal of Trauma: Injury, Infection, and Critical Care, 1988

ABSTRACT

Journal of Operations Management, 1989

The heavilydebated Wagner-Whitin algorithm is known to produce optimal ordering policies for mini... more The heavilydebated Wagner-Whitin algorithm is known to produce optimal ordering policies for minimal-cost dynamic lot--sizing problems. In an earlier paper in this journal, Evans showed that the Wagner-Whitin algorithm is essentially a shortest path computation on an acyclic network, and presented a simple O(n2) computer implementation with low storage requirements.

International Journal of Flexible Manufacturing Systems, 1994

A new optimization model is discussed for the design of cellular manufacturing systems. It is bas... more A new optimization model is discussed for the design of cellular manufacturing systems. It is based on an integer programming formulation that updates some other models by eliminating redundant machine assignment and cost coefficients dependent on cell configuration. To reduce computational burdens, a simplified integer programming model and a decomposition algorithm are proposed. Several computer solutions were performed to evaluate the performance of the new model. The computational results are discussed.

Decision Sciences, 1991

Lot suing is a significant aspect of the materials requirement planning (MRP) production planning... more Lot suing is a significant aspect of the materials requirement planning (MRP) production planning process. Although its perceived importance has declined as a result of system maturation, more widespread just-in-time (JIT) orientations and the development of satisfactory heuristics, ...

Decision Sciences, 1985

The maximum expected covering location problem (MEXCLP) is reformulated using a separable pmgramm... more The maximum expected covering location problem (MEXCLP) is reformulated using a separable pmgrammhg approach. The multing formulation-nonlinear maximum apaed coming location pmblan (NMEXCLP)-guarantas optimality and also solves more quickly than previous heuristic approaches. NMEXCLP allows two important extensions. First, minor formulation changes allow the specification of the minimum number of times each node is to be covmd in order to satisfy expected coverage criteria Second, coverage matrices can be constructed that consider two different types of coverage simultaneously. Both atensions are useful for ambulance location problems and are demonstrated in that setting. Phdng.

Decision Sciences, 1991

Improvement on existing techniques for multilevd lot sizing in material requirements planning was... more Improvement on existing techniques for multilevd lot sizing in material requirements planning was sought by developing a theoretical and mathematical basis for the problem. Such a foundation was employed 10 design a heuristic which was superior in both cost performance and computational efficiency, and provided consistent results regardless of designated environmental factors. This reprrxnts a significant advantage over other algorithms tested here and within the literature in that their performances are dependent upon various lot-sizing environmental factors.

Computers & Operations Research, 1993

... TIES IN THE HYPERCUBE MODEL TIMOTHY H. BuRWELL1!, JAMES P. JARVis2 and MARK A. McKNEW3 '... more ... TIES IN THE HYPERCUBE MODEL TIMOTHY H. BuRWELL1!, JAMES P. JARVis2 and MARK A. McKNEW3 'Department of Decision Sciences, Appalachian State University, Boone, NC 28608 ...Mark A. McKnew is Professor of Management at Clemson University. ... (3) J=l Intuitively ...

Computers & Operations Research, 1998

Mathematical programming models for manufacturing cell formation problems are primarily integer p... more Mathematical programming models for manufacturing cell formation problems are primarily integer programming models with the special structure of being “multidivision problems”. Lagrangian relaxation has been one of the best decomposition approaches and enabled the solution of problems of practical size. This research develops a partial termination rule for the Lagrangian relaxation algorithm. While the existing algorithm solves all submodels in each iteration, the partial termination rule recognizes early termination of some submodels. This results in a substantial reduction of computation while generating the same solution. The new termination rule is proven mathematically. Thus, its applicability extends beyond the solution of the manufacturing cell formation problem.

Computers & Operations Research, 1995

ABSTRACT We present a pure zerp-one integer programming model for determining single-item product... more ABSTRACT We present a pure zerp-one integer programming model for determining single-item production lot sizes in capacitated “long production run” environments, where each production period is dedicated to a single product, and where production of a given item may extend over more than one production period. All costs, as well as capacity, are time-varying, and include startup (changeover), reservation (opportunity), holding, and production costs. Holding and production cost may also vary within a period. The problem setting is effectively the single-item subproblem of the “multiple product cycling” case. Our a model is efficient primarily because of variable elimination strategies associated with capacity limitations. Although our formulation makes two simplifying assumptions versus previous research, these did not significantly hamper model performance. Experimentation on problems from the literature yielded a 93% optimality frequency, with less than 60 pivots required for 20 period problems, a tremendous efficiency improvement over previous models. As such, the model represents an excellent and practical first step toward efficiently solving multiple product problems on an industrial scale.

Socio-Economic Planning Sciences, 1984

Proceedings of the 24th conference on Winter simulation - WSC '92, 1992

Cornell Hotel and Restaurant Administration Quarterly, 1997

How can one buffet turn its tables in 40 minutes, while another needs go? A computer model can sh... more How can one buffet turn its tables in 40 minutes, while another needs go? A computer model can show where the holdups are and evaluate potential changes.

This article presents a unique heuristic model for purchased item lot-sizing. The model subsequen... more This article presents a unique heuristic model for purchased item lot-sizing. The model subsequently is tested using 20 historically popular sample problems. The development of heuristic lot-sizing models was initiated as a result of difficulties identified during evaluation of the multi-level lot-sizing problem encountered in using material requirements planning systems. The "technique for order placement and sizing" (TOPS) is based on the logic of the "incremental part-period algorithm," and incorporates four distinct phases. It compares incremental costs and benefits of revising an initial order release schedule by inserting new orders or shifting existing ones. Results of an experimental process exhibited single-line optimal solutions for all test cases. Additionally, execution times were similar to much simpler but less accurate techniques than those of the optimizing Wagner-Whitin routine.

Socio-Economic Planning Sciences, 1989

A simpIe regression model is developed to estimate the number of servers necessary to cover a reg... more A simpIe regression model is developed to estimate the number of servers necessary to cover a region, Data for the model were obtained within a research design that inciuded five replications of 180 experimental conditions. A total of 300 rectangular regions were generated, and a set covering location problem was solved for each region using three distance metrics. Statistical resuits established coverage radius, compactness, and the number of nodes in the region to be significant factors. The resulting regression model was applied to a South Carolina county. Its estimates are seen to be very close to the number of units needed to cover. The model is shown to be a convenient technique for quickly estimating the number of servers while exhibiting an error distribution that is conservatively biased towards overestimation.

Socio-Economic Planning Sciences, 1992

An application of a spatially distributed queuing model to an ambulance system is presented. The ... more An application of a spatially distributed queuing model to an ambulance system is presented. The purpose of this research was to assess the usefulness of a variation of the "hypercube" queuing model developed specifically for modeling an ambulance system. The model was applied to the emergency medical system of Greenville County, South Carolina using historical data. Results indicate that the model provides reasonably accurate estimates of system performance measures when the input parameters can be accurately specified.

Socio-Economic Planning Sciences, 1993

This research develops a workload balancing model that incorporates a preference list for a fixed... more This research develops a workload balancing model that incorporates a preference list for a fixed number of ambulance stations and simple concepts of queuing theory into a mathematical programming formulation. The workload balancing model is demonstrated on actual operating data from the Emergency Medical Service (EMS) system of Shanghai, P.R. China. Results indicate that the model is able to minimize the workload Imbalance among existing stations by assigning ambulance units on the basis of demand received by each station.

SIMULATION, 1994

Abstract This paper addresses the problem of modeling time-varied arrival rates in gicetcing syst... more Abstract This paper addresses the problem of modeling time-varied arrival rates in gicetcing systems. The approach is to break down a 24-hour period into small time durations such that an average arrival rate during the time duration can be reasonably viewed as constant. ...

Management Science, 1982

Page 1. MANAGEMENT SCIENCE Vol. 28, No. 7, July 1982 Printed in? USA POLICE PATROL-INITIATED ACTI... more Page 1. MANAGEMENT SCIENCE Vol. 28, No. 7, July 1982 Printed in? USA POLICE PATROL-INITIATED ACTIVITIES WITHIN A SYSTEMS QUEUEING MODEL* RICHARD C. LARSONt AND MARK A. McKNEW$ Officers in ...

The Journal of Trauma: Injury, Infection, and Critical Care, 1986

The Journal of Trauma: Injury, Infection, and Critical Care, 1988

ABSTRACT

Journal of Operations Management, 1989

The heavilydebated Wagner-Whitin algorithm is known to produce optimal ordering policies for mini... more The heavilydebated Wagner-Whitin algorithm is known to produce optimal ordering policies for minimal-cost dynamic lot--sizing problems. In an earlier paper in this journal, Evans showed that the Wagner-Whitin algorithm is essentially a shortest path computation on an acyclic network, and presented a simple O(n2) computer implementation with low storage requirements.

International Journal of Flexible Manufacturing Systems, 1994

A new optimization model is discussed for the design of cellular manufacturing systems. It is bas... more A new optimization model is discussed for the design of cellular manufacturing systems. It is based on an integer programming formulation that updates some other models by eliminating redundant machine assignment and cost coefficients dependent on cell configuration. To reduce computational burdens, a simplified integer programming model and a decomposition algorithm are proposed. Several computer solutions were performed to evaluate the performance of the new model. The computational results are discussed.

Decision Sciences, 1991

Lot suing is a significant aspect of the materials requirement planning (MRP) production planning... more Lot suing is a significant aspect of the materials requirement planning (MRP) production planning process. Although its perceived importance has declined as a result of system maturation, more widespread just-in-time (JIT) orientations and the development of satisfactory heuristics, ...

Decision Sciences, 1985

The maximum expected covering location problem (MEXCLP) is reformulated using a separable pmgramm... more The maximum expected covering location problem (MEXCLP) is reformulated using a separable pmgrammhg approach. The multing formulation-nonlinear maximum apaed coming location pmblan (NMEXCLP)-guarantas optimality and also solves more quickly than previous heuristic approaches. NMEXCLP allows two important extensions. First, minor formulation changes allow the specification of the minimum number of times each node is to be covmd in order to satisfy expected coverage criteria Second, coverage matrices can be constructed that consider two different types of coverage simultaneously. Both atensions are useful for ambulance location problems and are demonstrated in that setting. Phdng.

Decision Sciences, 1991

Improvement on existing techniques for multilevd lot sizing in material requirements planning was... more Improvement on existing techniques for multilevd lot sizing in material requirements planning was sought by developing a theoretical and mathematical basis for the problem. Such a foundation was employed 10 design a heuristic which was superior in both cost performance and computational efficiency, and provided consistent results regardless of designated environmental factors. This reprrxnts a significant advantage over other algorithms tested here and within the literature in that their performances are dependent upon various lot-sizing environmental factors.

Computers & Operations Research, 1993

... TIES IN THE HYPERCUBE MODEL TIMOTHY H. BuRWELL1!, JAMES P. JARVis2 and MARK A. McKNEW3 '... more ... TIES IN THE HYPERCUBE MODEL TIMOTHY H. BuRWELL1!, JAMES P. JARVis2 and MARK A. McKNEW3 'Department of Decision Sciences, Appalachian State University, Boone, NC 28608 ...Mark A. McKnew is Professor of Management at Clemson University. ... (3) J=l Intuitively ...

Computers & Operations Research, 1998

Mathematical programming models for manufacturing cell formation problems are primarily integer p... more Mathematical programming models for manufacturing cell formation problems are primarily integer programming models with the special structure of being “multidivision problems”. Lagrangian relaxation has been one of the best decomposition approaches and enabled the solution of problems of practical size. This research develops a partial termination rule for the Lagrangian relaxation algorithm. While the existing algorithm solves all submodels in each iteration, the partial termination rule recognizes early termination of some submodels. This results in a substantial reduction of computation while generating the same solution. The new termination rule is proven mathematically. Thus, its applicability extends beyond the solution of the manufacturing cell formation problem.

Computers & Operations Research, 1995

ABSTRACT We present a pure zerp-one integer programming model for determining single-item product... more ABSTRACT We present a pure zerp-one integer programming model for determining single-item production lot sizes in capacitated “long production run” environments, where each production period is dedicated to a single product, and where production of a given item may extend over more than one production period. All costs, as well as capacity, are time-varying, and include startup (changeover), reservation (opportunity), holding, and production costs. Holding and production cost may also vary within a period. The problem setting is effectively the single-item subproblem of the “multiple product cycling” case. Our a model is efficient primarily because of variable elimination strategies associated with capacity limitations. Although our formulation makes two simplifying assumptions versus previous research, these did not significantly hamper model performance. Experimentation on problems from the literature yielded a 93% optimality frequency, with less than 60 pivots required for 20 period problems, a tremendous efficiency improvement over previous models. As such, the model represents an excellent and practical first step toward efficiently solving multiple product problems on an industrial scale.

Socio-Economic Planning Sciences, 1984