- Email: [email protected]
Modelling the interrelationship between downtimes and uptimes of CNC machines
1176
Mathematical and Computer Modelling Reports
Eur. .I. o/d Rex Vol.
37,pp. 149-157, 1988
BUILDING
MODELS
OF VALUES
~LPH L. KEENEY Systems Science Department, University of Southern California, Los Angeles, CA 90089-0021, U.S.A.
Abstract-To achieve a set of objectives, whether they are made explicit or not, is the entire intent of decisionmaking. When they are explicitly stated, the objectives are often quantified with an objective function. Because of its critical role for decisionmaking, the objective function should be developed from first principles, sound logic, reasoned judgments, and carefully acquired consistent data. Unfortunately, in practice many objective functions are hastily chosen from a process that can at best be described as arbitrary. This paper presents a better alternative for developing the objective function, namely to construct it from a quality modelling effort. Key Words-Objective
Eur. J. o/d Res. Vol.
functions, decision analysis, utility functions, value model
37.pp.2542271, 1988
MODELING
THE INTERRELATIONSHIP BETWEEN AND UPTIMES OF CNC MACHINES
DOWNTIMES
YASH P. GUPTA Department of Management, University of Louisville, Louisville, KY 40292, U.S.A. TONI M. SOMERS and LEAGRAU Department of Information Systems and Operations Management, University of Toledo, Toledo OH 43606, U.S.A.
Abstract-Plant and equipment represent over 50% of the assets in most manufacturing industries. New technologies such as FMS are having a pervasive effect on technology adoption rates and the resultant productivity gains. The acquisition of CNC machines, which is an integral part of FMS, has been justified on financial grounds; however, this does not take the breakdown behavior of these machines into consideration. The downtime resulting from these breakdowns leads to loss of productivity. In this paper an attempt has been made to determine the interrelationship between the downtimes and uptimes of CNC machines using transfer function modeling. The models are tested using data from a farm equipment manufacturer. Key Words-Manufacturing,
reliability, maintenance, management
Tec/mo/. Forecarr. socidChmgeVol. 33.pp. 31l-323,1988
THE EVOLUTION
OF SOCIO-ECONOMIC R. B. HOFFMANand B. C.
MODELING
IN CANADA
MCINNIS
Waterloo Simulation Research Facility, University of Waterloo, Ontario, Canada Abstract-For the past 15 years the authors have been associated with a research program concerned with the development of structural economic models that had their origins in the input-output models of Leontief. This program has produced a set of conceptual tools embracing a new approach to socio-economic modeling which we term the “design approach”. This approach draws on general systems theory and control theory in application to large social systems. Also emerging from this program as its test prototype is a particular set of models designed for society wide resource analysis and a set of software tools within which design approach models can be designed, implemented, and operated. The design approach provides a new method of assessing technologies in regard to their overall socio-economic resource impact. The objective of this paper is to describe the unique institutional setting and the particular
Mathematical and Computer Modelling Reports
Eur. .I. o/d Rex Vol.
37,pp. 149-157, 1988
BUILDING
MODELS
OF VALUES
~LPH L. KEENEY Systems Science Department, University of Southern California, Los Angeles, CA 90089-0021, U.S.A.
Abstract-To achieve a set of objectives, whether they are made explicit or not, is the entire intent of decisionmaking. When they are explicitly stated, the objectives are often quantified with an objective function. Because of its critical role for decisionmaking, the objective function should be developed from first principles, sound logic, reasoned judgments, and carefully acquired consistent data. Unfortunately, in practice many objective functions are hastily chosen from a process that can at best be described as arbitrary. This paper presents a better alternative for developing the objective function, namely to construct it from a quality modelling effort. Key Words-Objective
Eur. J. o/d Res. Vol.
functions, decision analysis, utility functions, value model
37.pp.2542271, 1988
MODELING
THE INTERRELATIONSHIP BETWEEN AND UPTIMES OF CNC MACHINES
DOWNTIMES
YASH P. GUPTA Department of Management, University of Louisville, Louisville, KY 40292, U.S.A. TONI M. SOMERS and LEAGRAU Department of Information Systems and Operations Management, University of Toledo, Toledo OH 43606, U.S.A.
Abstract-Plant and equipment represent over 50% of the assets in most manufacturing industries. New technologies such as FMS are having a pervasive effect on technology adoption rates and the resultant productivity gains. The acquisition of CNC machines, which is an integral part of FMS, has been justified on financial grounds; however, this does not take the breakdown behavior of these machines into consideration. The downtime resulting from these breakdowns leads to loss of productivity. In this paper an attempt has been made to determine the interrelationship between the downtimes and uptimes of CNC machines using transfer function modeling. The models are tested using data from a farm equipment manufacturer. Key Words-Manufacturing,
reliability, maintenance, management
Tec/mo/. Forecarr. socidChmgeVol. 33.pp. 31l-323,1988
THE EVOLUTION
OF SOCIO-ECONOMIC R. B. HOFFMANand B. C.
MODELING
IN CANADA
MCINNIS
Waterloo Simulation Research Facility, University of Waterloo, Ontario, Canada Abstract-For the past 15 years the authors have been associated with a research program concerned with the development of structural economic models that had their origins in the input-output models of Leontief. This program has produced a set of conceptual tools embracing a new approach to socio-economic modeling which we term the “design approach”. This approach draws on general systems theory and control theory in application to large social systems. Also emerging from this program as its test prototype is a particular set of models designed for society wide resource analysis and a set of software tools within which design approach models can be designed, implemented, and operated. The design approach provides a new method of assessing technologies in regard to their overall socio-economic resource impact. The objective of this paper is to describe the unique institutional setting and the particular