Manufacturing Resource Planning Research Articles

A new framework for MRP systems to be effective in engineered-to-order environments

Present day manufacturing resource planning (MRP) systems do not perform well in engineered-to-order (ETO) environments. A study of the use of MRP systems by ETO companies has led to the development of a new framework for manufacturing planning systems. New features allow better coordination of activities in the areas of engineering, material acquisition, production, and delivery. The new framework especially addresses the problem of planning with uncertain information which is characteristic of an ETO environment.

Modelling the changing apparel supply chain

This paper describes a research project funded by the Engineering and Physical Sciences Research Council. Twenty case‐study companies operating across a range of industrial sectors participated in the project. Sectors chosen for the development of these architectures were those where the use of the traditional manufacturing resource planning (MRPII) model is not the optimum operating solution. In particular, the paper describes the process mapping and analysis approach applied to the study of a sector‐based group of apparel manufacturing companies who collaborated in the research. The planning issues that confront the companies, the control solutions they employ in response to their present commercial environment as they seek to address the changing demands being made of the industry are outlined. A generic planning and control reference architecture developed from the study for the apparel sector is presented.

Successful implementation of advanced manufacturing technology: a cross sectional survey

The purposes of this study are to determine (1) the frequency of use of advanced manufacturing technologies (AMTs) in south-western United States manufacturing firms, (2) which AMTs have the greatest perceived impact on value, and (3) which have been most successfully employed. The study population consisted of senior manufacturing managers of companies in SIC 34 through 39 located in six south-western states. The study determined that the most frequently used AMT was computer-aided design (CAD), used by 75% of the respondents. Manufacturing resource planning (MRP), computer numerically controlled (CNC) machining, statistical process control (SPC), and computer aided manufacturing (CAM) were used by at least one-third of the respondents. Automated process monitoring and automated material handling were the least used AMTs. Those AMTs perceived to have the greatest positive effect on producer's value are CNC machining, closed loop process control, automated process inspection, flexible manufacturing cells (FMC), robotics, computer-aided manufacturing, computer integrated manufacturing (CIM), and automated process monitoring. The AMTs could be classified into four categories based upon their effect on the two dimensions of value quality and cost. These categories were high value affecting, quality affecting, cost affecting, and low value affecting. Four of the high value affecting AMTs were among those rated as having the highest overall degree of success. However, the study found that dissonance exists between the AMTs which are most used and those which are perceived to have the greatest effect on value.

Karmarkar’s and interaction/prediction algorithms for hierarchical production planning for the highest business benefit

This paper explores the hierarchical production planning (HPP) problem of flexible automated workshops (FAWs), each of which has a number of flexible manufacturing systems (FMSs). The objective is to decompose medium-term plans (assigned to an FAW by ERP/MRP II) into short-term plans (to be executed by FMSs in the FAW) for the highest business benefit. Here, ERP is short for enterprise resource planning and MRP II short for manufacturing resource planning. For practical purposes, the HPP problem is modeled after a linear programming (LP) model. Because the scale of the model for a general workshop is too large to be solved by the simplex method on a personal computer, Karmarkar’s algorithm and an interaction/prediction algorithm are used to solve the model, the former for the large-scale problems and the latter for the very large scale. With the help of the programs written by using the above-mentioned algorithms and sufficient HPP examples, Karmarkar’s algorithm, the interaction/prediction algorithm and the LP method in Matlab 5.0 are compared, the results showing that the proposed approaches are very effective.

Developing an Integration Framework to Support the Information Flow Between PDM and MRP

This paper proposes a methodology to support the integration of information flow between the applications of product data management (PDM) and manufacturing resource planning (MRP). A three-level structure including model development, model analysis, and system implementation was developed. An approach applying the concepts of semantic similarity to find the "common" objects used in different business applications was also proposed. These objects were used as a buffer for the information integration. In addition, a set of business rules was developed to govern the information flow between PDM and MRP. The proposed methodology has been implemented by integrating two commercial PDM and MRP software modules.

A matrix formulation for integrating assembly trees and manufacturing resource planning with capacity constraints

This paper introduces a new matrix-based formulation for assembly trees which facilitates solving the manufacturing resource planning (MRP) problem including resource constraints for a large class of problems. The algorithm seamlessly integrates assembly tree information, capacity requirements, and traditional manufacturing resource planning; the algorithm allows for a large class of capacity limitations, and solves these problems without requiring a manager to iteratively adjust the MRP schedule.

Framework for the evaluation of an information system

Manufacturing Resource Planning (MRPII) systems offer many organisations the opportunity to reap a wide variety of strategic and operational benefits. However, even though many of these benefits are suitable for evaluation within traditional accountancy frameworks, it is the intangible and non-financial benefits, together with the indirect project costs, which complicate the justification of Information Technology (IT) and Information Systems (IS). As a result, many companies are finding themselves unable to assess the full implications of their MRPII investments, thus amounting to an appraisal process limited to the benefits and costs financially quantifiable. This therefore questions the predictive value of those justification processes that make use of traditional appraisal techniques. As a result, many companies are forced to adopt one of the following strategies: (i) a refusal to undertake IT/IS projects whose benefits and costs are not financially quantifiable; (ii) invest in IT/IS projects as an act of faith; or, (iii) use creative accounting as a method of passing the budgetary process. This paper reviews the published literature and offers a taxonomy of investment appraisal techniques, together with their inherent limitations when used as part of an MRPII justification process. The author then presents a conceptual framework for the evaluation of IT/IS investments in manufacturing, with a particular focus on MRPII. The proposed framework: (i) distinguishes the different types of justification processes necessary; (ii) accounts for the selection of the most appropriate technical specification and supplier(s); (iii) identifies human and organisational issues; (iv) acknowledges the limitations inherent in traditional appraisal techniques; (v) suitably places the implementation process within project evaluation; and (vi) integrates a feedback mechanism to ensure that when the system has been implemented, a management review assesses whether the planned project objectives have been realised. Finally, the paper concludes with those implications associated with the development of a descriptive MRPII evaluation framework.

Empirical testing of an information systems evaluation framework

The justification of information technology (IT) and information systems (IS) is inherently complex, since there are a large range of benefits that are intangible and non-financial, which thus present much difficulty during investment appraisal. However, it is not only the benefits of IT/IS that present this difficulty but also the range of indirect costs associated with an IT/IS deployment. Therefore, many justification processes are often exclusively based on those financially tangible benefits and costs that can be accounted for within traditional appraisal techniques. This paper describes the testing of a novel framework for the evaluation of IT/IS in manufacturing, with a particular focus on manufacturing resource planning (MRPII). This proposed approach addresses many of the limitations inherent in traditional appraisal techniques. The testing of this framework is then carried out through describing a case experience of a small/medium enterprise (SME) that was unable to fully justify its capital expenditure on MRPII, whilst using traditional approaches to financial appraisal. As a result of their inability to financially justify their expenditure, the company adopted a simple cost/benefit analysis, and invested as an act of faith. The author describes the idiosyncrasies of the case study company, and details the problems experienced during his attempts to evaluate, implement and realise the holistic implications of their MRPII investment. Although the IS was operational for a period of time, it was eventually deemed a failure, due to a range of human and organisational issues. This paper identifies those factors, and describes how the company addressed them before embarking on a process of bespoke system development and implementation. The author then tests the proposed hypotheses, which underpin the constructs within the previously presented IT/IS evaluation framework, against both vendor purchased software and a bespoke developed system

Enterprise Resource Planning as the Trojan Horse for New Rules of Operations Management

The control of operations, for example; the flow of materials, the scheduling of production, the planning of capacity – these are central problem in operations management. A substantial body of technique, with attendant technologies, has been developed to facilitate the problem of control of operations. One such technique is Manufacturing Resource Planning (MRP). This technique has developed in power and scope in concert with the development of power in computer based technology. From the perspective of the operations management literature, MRP has evolved into MRP II, and now into Enterprise Resource Planning (ERP). MRP, and MRP II are systems that are embedded within the operations function, and can be controlled legitimately by the operations function; ERP is fundamentally different. ERP systems in their model implementation are enterprise wide, integrated systems. As an enterprise wide system, ERP has created an opportunity to distance the power to influence operations actions from the location of the function. This change has significant implications for the companies adopting the technology, and more specifically, for the profession of operations management. This paper develops a framework of analysis for this change, presents a set of small cases, and discusses some implications that can be drawn from the analysis. The “three arenas of information use – sense making, knowledge creating, and decision making” (Choo 1998, p.3) must be allowed to energize each other and this can only happen if organization wide information systems, such as ERP, respect and empower situated action, enable ambiguity, and allow the use of multiple interpretive frames as managers interact with the situations of operations management.

Responsive manufacturing demands alignment of production control methods to business drivers

For the past 20 years production planning and control has been dominated by manufacturing resource planning (MRPII) and its antecedents. The authors are completing case study based research that is aimed at developing novel planning and scheduling reference models for industrial sectors where the MRPII paradigm is not appropriate. It outlines the process mapping approach adopted for data capture within the case study companies and the use of ARIS, Scheer’s enterprise modelling tool, for the production of sector reference models.

Achieving MRPII Class A status in an SME ‐ A successful case study

Implementing a Manufacturing Resource Planning (MRPII) system represents a significant challenge for all those involved in such projects. Indeed, many such change programmes result in failure or fall short of achieving the significant benefits that such systems have to offer. This paper investigates one such implementation within a medium‐sized company in the medical packaging industry. The application of behavioural and performance metrics was applied to monitor and facilitate the attainment of MRPII to Class A status. A longitudinal evaluation of the project is outlined and highlights a range of factors that ultimately affect the degree of success of MRPII implementation.

Conception and Implementation of an Object Request Broker for the Integration of the Process Level in Manufacturing Systems

In order to be able to react quickly to altering production states, planning tools such as Manufacturing Resource Planning and Enterprise Resource Planning heavily rely on up to date information about the process itself. Thus, access to process level data is one of the most important issues within the production industry. However, the process level lacks support for open, connective communication systems as the number of incompatible fieldbus systems shows. Current solutions, e.g., OLE for Process Control, only focus on a unified interface to the process level, but do not allow to access the functionality of a field device directly. The approach presented in this paper introduces FIMO, the Fieldbus Messaging Object Request Broker, to be deployed in field devices and utilizing the existing fieldbus protocols. With the use of FIMO, devices connected to a fieldbus can be seamlessly integrated in the whole manufacturing hierarchy. The paper gives a brief overview of thestate of the art for accessing process level data. Then, the FIMO architecture is presented in detail including its core services and the mapping of the communication services to the underlying fieldbus system.

Implementing computerized technology: an organizational analysis.

Why do some organizations succeed and others fail in implementing the innovations they adopt? To begin to answer this question, the authors studied the implementation of manufacturing resource planning, an advanced computerized manufacturing technology, in 39 manufacturing plants (number of individual respondents = 1,219). The results of the plant-level analyses suggest that financial resource availability and management support for technology implementation engender high-quality implementation policies and practices and a strong climate for implementation, which in turn foster implementation effectiveness--that is, consistent and skilled technology use. Further research is needed to replicate and extend the findings.

Conditions for the successful implementation of finite capacity/MRPII hybrid control systems

Manufacturing resource planning II (MRPII) is the most widely employed methodology for production planning and control. Many authors, however, have stated that the fundamental basis of MRPII is flawed: that is to say, scheduling is based on fixed manufacturing lead times/lot sizes with infinite capacity. There has also been great interest in alternative methodologies such as optimized production technology (OPT) which plans to finite capacity. As a result, there are now several software houses who offer finite capacity scheduling (FCS) tools designed to operate alongside MRPII packages. These provide detailed finite capacity planning while retaining the database infrastructure of MRPII. Such hybrids claim to give the benefits of FCS to established MRPII users without the need for re-implementation. This paper describes the operation of such hybrids. Based on a case study drawn from the automotive components industry, it discusses the pitfalls that might be experienced without careful consideration of planning methods in relation to Bill of Material (BOM) structures. In particular, it shows that for a hybrid to be successful, it is necessary to consider the system as a whole, rather than considering FCS as a simple addition to MRPII.

The two level master production schedule and planning bills in a just in time MRP context

The evolution of industrial firms has recently passed from a strong growth phase to a phase where there is a greater complexification of products: widening the range of products in catalogues, diversification and personalization of models. The current trend is to use, with production management techniques such as classical manufacturing resource planning (MRP2), the concept of two level master production schedule (MPS), using planning bills with percentages indicating the probability that such or such an option will be used. This necessitates, however, the implementation of a rigorous approach to continuous improvement using just in time (JiT) and total quality (TQ) concepts. In the first part of our paper we discuss principles of operating two level MPS; secondly, we analyze these effects on management and organization. Our paper is based on a case study.

Genetic algorithm to production planning and scheduling problems for manufacturing systems

Fundamental and extended multi-objective (MO) models are designed to address earliness/tardiness production scheduling planning (ETPSP) problems with multi-process capacity balance, multi-product production and lot-size consideration. A canonical genetic algorithm (GA) approach and a prospective multi-objective GA (MOGA) approach are proposed as solutions for different practical problems. Simulation results as well as comparisons with other techniques demonstrate the effectiveness of the MOGA approach, which is a noted improvement to any of the existing techniques, and also in practice provides a new trend of integrating manufacturing resource planning (MRPII) with just-in-time (JIT) in the production planning procedure.

The implementation of a model for integration of MRP II and TQM

A way of initiating and sustaining the implementation of total quality management (TQM) by exploiting the widely adopted manufacturing resource planning (MRP II) is presented. A detailed analysis of MRP II software has found that they have a number of inherent features that can be further extended to organizational performance including operations efficiency, responsiveness, company‐wide problem‐solving capability and product quality. This paper contributes in the development of a model for the MRP II with the incorporation of mechanisms to initiate a culture change in the organization towards TQM. In the adaptation of MRP II to guide the implementation of TQM, a structural analysis technique was proposed to help develop a model and methodology for the integration. In the structural analysis, an IDEF model of a “reference” company structure was created to illustrate and describe the integration. The reference company, which is a lamp manufacturer, is used to illustrate the systematic implementation of the TQM philosophy through adaptation of the MRP II software. The study demonstrates that MRP II can be adapted to provide the drive for effective implementation of TQM for productivity and profits.

Manufacturing classifications: relationships with production control systems

Since the early 1970s, production planning systems have evolved from material requirements planning (MRP) through manufacturing resource planning (MRPII) into enterprise resource planning (ERP) with simultaneous development of related control systems such as theory of constraints (epitomised by OPT), just‐in‐time (JIT), etc. One key area for all manufacturing companies is the planning and control function. There is a wide range of generic proprietary software available that aims to meet a company’s planning and scheduling requirements. The difficulty experienced by many companies is not only in examining available software, but also in understanding the match between business needs and the capabilities of that software. This paper first sets out some common manufacturing classification systems, then attempts to map them against accepted paradigms for production planning and control approaches. Analysis confirms the need for a more rigorous approach to software selection, and the need for a complete understanding of the drivers of the production control process before this can be achieved. The paper goes on to discuss a method for mapping these drivers, with the aim being to create a series of reference models for production planning and scheduling.

Challenges and issues in scaling commercial production of conifer somatic embryogenesis

Significant progress has been made toward commercial implementation of a large-scale somatic embryogenesis (SE) production process for spruce somatic embryos. The major emphasis was to overlay the established principles and disciplines of “Manufacturing Resource Planning” (MRP) onto the original laboratory-scale protocols used to produce spruce SE and SE products. This approach required extensive and precise characterization of the inputs, actions, labor requirements, and quantification of the resulting outputs for each process step. In addition, computerized process and inventory tracking programs were developed and incorporated. The information collected enabled identification and clear understanding of the biological and physical constraints within the process, and enabled optimization of SE production planning, costing and scheduling activities. Standard operating procedures (SOPs) for each step of the SE process were developed and implemented. The net effect was the productivity of the scaled laboratory spruce SE process was increased by more than 300% without any additional labor inputs, while the direct cost-of-production for a “finished” somatic seedling was reduced by more than 70%.

A genetic algorithm for multi-level, multi-machine lot sizing and scheduling

This contribution introduces a mixed-integer programming formulation for the multi-level, multi-machine proportional lot sizing and scheduling problem. It also presents a genetic algorithm to solve that problem. The efficiency of that algorithm is due to an encoding of solutions which uses a two-dimensional matrix representation with non-binary entries rather than a simple bitstring. A computational study reveals that the proposed procedure works amazingly fast and competes with a tabu search approach that has recently been published. Scope and purpose The logic of Manufacturing Resource Planning (MRP II) is implemented in most production planning software packages. In the short-term scope, where lot sizing and scheduling has to be done, MRP II systems basically pass three phases: First, lot sizes are computed while disregarding capacity constraints. Multi-level product structures are taken into account in a level-by-level manner starting with end items. Second, lot sizes are adapted to meet capacity restrictions. This time, precedence relations among items are not taken into account. Finally, sequence decisions are made. Following this strategy is reported to result in high work-in-process and long lead times. To cure these shortcomings, an approach for simultaneous lot sizing and scheduling is required where multi-level product structures and several scarce capacities are taken into account. Unfortunately, such methods have not been presented yet. To close this gap is our aim.