Johan Wortmann

Integrating MRP and finite capacity planning

Traditional production control systems based on the manufacturing resource planning concept do not sufficiently support the planner in solving capacity problems, ignore capacity constraints and assume that lead times are fixed. This leads to problems on the shop floor, that cannot be resolved in the short term. This paper focuses on solving these capacity problems by improving capacity planning at the material requirements planning MRP level through integration of MRP and finite capacity planning. This results in a planning method for simultaneous capacity and material planning. The planning method is based on a new and more accurate primary process model, giving the planning algorithm more flexibility in solving capacity problems. The algorithm is based on advanced scheduling techniques and uses aggregated information, thus combining speed and accuracy. The algorithm is designed to use the available flexibility: alternative routeings, safety stock, and replanning of production orders and requirements. Th...

Managing condition‐based maintenance technology: A multiple case study in the process industry

Purpose – Condition‐based maintenance is the diagnosis of component failure or a prognosis of a components time to failure. The aim of this paper is twofold: a summary of the main assumptions regarding condition‐based maintenance found in the literature into eight postulates, and a comparison of the postulates against industrial practice. The postulates were formulated regarding the technical system, the managerial system and workforce knowledge.Design/methodology/approach – The postulates were examined in a multiple case study of five large firms in the process industry.Findings – The results indicate that some postulates were supported with empirical findings. Limited or no support was found for postulates concerning the application of prognostic activities, use of dedicated software, use of procedures, use of training, and the active management of domain‐related knowledge availability.Practical implications – Practitioners can use the eight postulates as key elements in the management of condition‐bas...

Fuzzy sustainability incentives in new product development: An empirical exploration of sustainability challenges in manufacturing companies

Purpose – This paper investigates the challenges encountered by manufacturing companies in managing sustainability in new product development (NPD). It describes six case studies of manufacturers aiming for sustainability improvements but experiencing difficulties in implementing them. Design/methodology/approach – The paper starts with a literature study. Academic literature offers explanations as to why manufacturers want to implement sustainability in NPD, and suggests methods for such implementations. This paper employs the systems theory of control to build a research framework for analyzing the challenges. Empirical data are gathered through workshops and interviews with NPD managers in the case companies. Findings – In-depth analyses have provided three insights. First, the study shows that sustainability pressures and incentives in a firms contexts can be fuzzy or even absent. The fuzziness of sustainability incentives is often neglected in the literature on sustainability and NPD. Second, the ca...

Typology of condition based maintenance

Purpose – The purpose of this paper is the development of an empirically based typology of condition based maintenance (CBM) approaches, including the relevant characteristics and requirements.Design/methodology/approach – An exploratory case study was conducted in a major gas production facility. The CBM typology that resulted from this case study was subsequently tested against a large set of CBM literature.Findings – In the literature, CBM is usually presented as a single theory or practice. The paper finds that CBM in fact includes several different approaches and that each of the approaches is only suitable in situations where the specific characteristics of the approach match the situational characteristics. Aided by these findings, a new typology for CBM was developed. The typology is based on the method for obtaining the expected value, or trend (through statistical vs analytical modeling) and the type of data used (process vs failure data). A subsequent literature survey reveals that the proposed...

Production monitoring and control with intelligent products

Advances in production planning and control in recent decades have focused on increasing the sophistication of the planning function. For good reasons, these advances have led to the centralisation of the planning function in production. However, the sophistication of the planning function should be in balance with monitoring and control of the plan. Monitoring and control are by their nature decentralised, beginning on the shop floor, and, therefore, the desire for greater sophistication in monitoring and control leads to renewed interest in decentralised and localised approaches. This paper demonstrates the possibility of using intelligent products for decentralised monitoring and control. Intelligent products are aware of their local context and can negotiate with local manufacturing resources. As such, local solutions to problems can be proposed directly when problems occur. With the advancement of the ‘Internet of Things’, such a scenario is likely to become feasible in the near future. The paper demonstrates the viability of such an approach through a simulation study, in which robustness is included as an additional measure of performance. The results of the simulations are encouraging.

Automated runtime repair of business processes

Concurrent business processes frequently suffer from mutual interference, especially in highly distributed service environments, where resources are shared among different stakeholders. Interference may be caused by supposedly stable case-related data, which are modified externally during process execution and may result in undesirable business outcomes. One way to address this problem is through the specification of dependency scopes, that cover critical parts of the process, and intervention processes, which are triggered at runtime to repair the inconsistencies. However, for complex processes, the manual specification of the appropriate intervention processes at design time can be particularly time-consuming and error-prone, while it is difficult to ensure that all important intervention cases are taken into account. To overcome this limitation, we propose an approach for automating the generation of intervention processes at runtime, by using domain-independent AI planning techniques. This way, intervention processes are composed on the fly, taking into account the characteristics of the business process in execution, the available compensation activities, and the properties that have to be fulfilled to recover from the erroneous situation. A prototype has been implemented and evaluated on a real case study of a business process from the Dutch e-Government.

Coordination activities of human planners during rescheduling : case analysis and event handling procedure

This paper addresses the process of event handling and rescheduling in manufacturing practice. Firms are confronted with many diverse events, such as new or changed orders, machine breakdowns, and material shortages. These events influence the feasibility and optimality of schedules, and thus induce rescheduling. In many manufacturing firms, schedules are created by several human planners. Coordination between them is needed to respond to events adequately. In this paper, the practice of coordination during event handling is analysed by an extensive case study. The study shows that human planners spend much time in communicating events and in negotiating rescheduling solutions. Because many events demand a quick response, the possibilities for coordination are restricted by time constraints. The paper proposes a procedure to structure the event handling process. This procedure helps a scheduler to select an appropriate response to an event by evaluating its influence on schedule feasibility and the time available for coordination and rescheduling. The use of the procedure in the case company has led to improved rescheduling performance through a reduction of scheduler interactions and increasing coordination efficiency. The procedure contributes to traditional planning frameworks and paradigms, and supports the conscious selection and use of rescheduling methods in manufacturing practice.

ICT issues among collaborative enterprises: From rigid to adaptive agent-based technologies

In this paper a review is presented of the current trends in IT interorganizational integration. A special emphasis is put on the Virtual Enterprise case. It is argued that the conceptual, structural and technological changes in the enterprise-to-enterprise interaction are producing a paradigm shift in how the conceptualization and design of future ICT systems. The emergences of component and agent technologies are important factors in this paradigm shift. The main features of the agent paradigm are presented, namely empowerment and cooperative interaction, and a short review given of the frameworks, tools and other technology related aspects, like code mobility and mobileagent systems. Finally, two mobile agent systems are presented.

Joint operational decision-making in collaborative transportation networks: the role of IT

Purpose – This paper addresses horizontal supply chain collaboration among autonomous freight carriers in the less-than-truckload industry. The main purpose of the paper is to identify and explain the challenges with joint operational decision-making in this context and investigate the precise role of information technology (IT) therein. Design/methodology/approach – Empirical evidence is gathered by means of exploratory and explanatory case research, with multiple cases at the planning departments of European freight carriers operating in collaborative transportation networks. Findings – Collaborating carriers face fundamental challenges in joint operational planning and control of collaborative transportation, despite the broad availability of state-of-the-art IT. These operational supply chain challenges can be explained by technological differences of the available IT applications, which hinder integration. Research limitations/implications – Any expectations with regard to state-of-the-art XML or EDI...

Intelligent products for enhancing the utilization of tracking technology in transportation

Purpose – Many transportation companies struggle to effectively utilize the information provided by tracking technology for performing operational control. The research as presented in this paper aims to identify the problems underlying the inability to utilize tracking technology within this context. Moreover, this paper aims to contribute to solving these problems by proposing a set of design principles based on the concept of intelligent products. Design/methodology/approach – The study as described in this paper adopts a design science research methodology consisting of three phases. First, a case study in a transportation company has been performed to identify the problems faced when utilizing tracking technology. Second, to overcome these problems, a set of design principles has been formulated. Finally, a prototype system based on the design principles has been developed and subjected to experimental and observational evaluation. Findings – This paper identifies the problems associated with the uti...