Engineering change: A theoretical assessment and a case study

The competitive playground where nowadays firms struggle to survive has rapidly become unforeseeable: product life cycle has shrunk, becoming even shorter than in the past, and world-wide market is suffering for a strong customer differentiation which led to an increasingly wide product mix. In this industrial environment, the engineering change process is getting more and more attention throughout the branches of industry, as it appears as a critical process which seeps into the operations management core, thus influencing the overall firm's performances. A brief state-of-the-art in the area of engineering change is firstly presented. Then a proposal of classification and a new methodology for an effective engineering change process management are suggested. The new proposed methodology has been successfully applied to a real-life manufacturing system and the related case study is reported at the end of the paper.     

Quality management and performance: a comparison between the UK and Turkey

Purpose: The aim of this article is to detail the correlation between quality management, specifically its tools and critical success factors, and performance in terms of primary operational and secondary organisational performances.

Design/methodology/approach: Survey data from the UK and Turkey were analysed using exploratory factor analyses, structural equation modelling and regression analysis.

Findings: The results show that quality management has a significant and positive impact on both primary and secondary performances; that Turkish and UK attitudes to quality management are similar; and that quality management is widely practised in manufacturing and service industries but has more statistical emphasis in the manufacturing sector. The main challenge for making quality management practice more effective lies in an appropriate balanced use of the different sorts of the tools and critical success factors.

Originality/value: This study takes a novel approach by: (i) exploring the relationship between primary operational and secondary organisational performances, (ii) using service and manufacturing data and (iii) making a cross-country comparison between the UK (a developed economy) and Turkey (a developing economy).

Limitations: Detailed contrast provided between only two countries.     

Modelling and controlling product manufacturing systems using bond-graphs and state equations: Continuous systems and discrete systems which can be represented by continuous models

This paper presents an approach to the modelling and control phases involved in a cooperative process of design and management of the manufacturing systems. Modelling the evolution of the production flow, in the different sections of the system, is based upon the use of the bondgraph methodology in order to reach the state formalism which constitutes one of the modern representations of automation. The class of the systems studied ranges from continuous systems to discrete systems, which can be represented by a continuous approach according to the level of approximation required. The first part of this paper is dedicated to the development of generic models associated with the various basic entities of the manufacturing systems. Then, the bondgraph model of any system is obtained by assembling generic models in relation to the implementation of the means of the studied system, thus guaranteeing a representation which is quite close to the engineering sketches. Finally, switching to the state equation is performed systematically with the easiness provided by this formalism while taking into account the causality principle. An application, involving most of the elementary models developed, concludes the paper.     

The effect of the drum-buffer-rope (DBR) approach on the performance of a synchronous manufacturing system (SMS)

The main objective of any manufacturing system is to organize the resources in a shop floor for effective transformation of raw materials into finished products. Synchronous manufacturing (SM) is a manufacturing management philosophy that has a set of principles, procedures and techniques where every action is evaluated in terms of a common global goal of the organization (Seetharama et al., 1997, Production Planning and Inventory Control). A manufacturing system that adopts the above principle is called as synchronous manufacturing system (SMS). In order for a manufacturing plant to achieve the benefits of a synchronous operation, a logistical manufacturing (SM) is a manufacturing management philosophy that has a set of principles, procedures and techniques where every action is evaluated in terms of a common global control system that is manageable and results in predictable performance is required. The drum-buffer-rope (DBR) approach, which is a generalized system, satisfies the above requirements through computer simulation. This paper focuses on the effect of DBR principles on the performance of a synchronous manufacturing system. A case study has been taken up in a small-scale industry and analysis has been carried out on the effect of the DBR approach on the performance of the system. This work has been performed on an IBM/PC compatible system using the promodel software and C language.     

Responding to discontinuities in product-based service supply chains in the COVID-19 pandemic: Towards transilience

PurposeIn this study, we identify and characterise how organisations have responded, in ways ranging from restoration to radical change, to discontinuities in their product-based service (PBS) supply chains during the COVID-19 pandemic.Design/methodology/approachFollowing a theoretical approach that integrates transilience and panarchy theory as a response strategy in PBS supply chains, our qualitative study involved collecting data through 19 semi-structured interviews at six manufacturing firms during the first 6 months of the COVID-19 pandemic (i.e., March to August 2020) and triangulating the findings with the secondary data and that from an industry workshop. Following an inductive approach, we performed thematic data analysis in Nvivo software package.FindingsThe findings suggest characterising discontinuities in PBS supply chains as unmanageable external supply-side, demand-side or interactional discontinuities or other manageable deliberate or forced organisational discontinuities. Following that characterisation, we developed a conceptual framework combing both resilience and transformation into new service opportunities.Research limitations/implicationsWe gained insights into the first-response abilities and ways of coping among manufacturing firms during the COVID-19 pandemic. Though our findings capture a contemporary, eye-of-the-storm perspective on future directions, a longitudinal study on the pandemic could further validate and extend the modes of response that complement mitigation with the ability to accelerate change or innovation of internal process or external service offerings.Originality/valueCombining current literature with lessons learned from the firms' immediate responses, this paper's overview and characterisation of discontinuities following the COVID-19 outbreak in PBS supply chains demonstrate how manufacturing firms can foster transilience. As such, it integrates product-based supply chain discontinuities into the domain of service-based supply chains.     

Integration of CAD/CAM and production control in sheet metal manufacturing — an application area of operations research

Abstract

This paper describes a process planning system for sheet metal parts. This system has capabilities to deliver process planning data just in time. The change of tools, processes and even machines for manufacturing of the parts is possible at the shop door after design has been finished.

The sequence of the production planning steps carried out can be changed. In this way the system can be adapted to the requirements of different sheet metal manufacturing companies.

More detailed information is given about the methods used for nesting of the workpieces on the sheets to be produced.     

Tardiness heuristic for scheduling Flexible Manufacturing Systems

Abstract

This paper evaluates the tardiness performance of a sampling-based adaptive heuristic in a dynamic manufacturing environment. A test bed, following a real world manufacturing system, has been developed. The proposed algorithm has been implemented in this simulated environment. After fine tuning the algorithm, it has been tested in various shop conditions. The results of these simulation studies are summarized.     

Developing a manufacturing vision

The concept of a manufacturing vision is introduced as a company specific, commonly shared, holistic picture of the way in which future manufacturing in the company will function. First is presented what a manufacturing vision is, and then is presented a five-step framework in which such a manufacturing vision may be developed. A manufacturing vision is regarded as a bridge between the mission, goals, and strategies of an industrial enterprise and the detailed design of a manufacturing system. Such a bridge may ensure that manufacturing is able to make a relevant strategic contribution to developing and sustaining the competitiveness of the company and may serve as a guide for innovation and integration of the various elements of a manufacturing system. The paper rests on action research projects in more than ten industrial companies, and the experiences gained are discussed in a section on issues related to the development process including experimentation without fear of losing face, participation and involvement of managers and employees, and finally the outset for a manufacturing vision. To give an example of a manufacturing vision the paper also very briefly introduces a case of a medium-sized supplier of welded parts and equipment for a number of different industries.     

A two-phase robot selection procedure

In this paper, a two-phase methodology is proposed for robot selection. In phase 1, data envelopment analysis is used as a means to determine the technically efficient robot alternatives, considering cost and technical performance parameters. Using data envelopment analysis permits us to consider the fact that the performance parameters specified by the vendors are generally unattainable in practice. In the second phase, a fuzzy robot selection algorithm is utilized to rank the technically efficient robots according to both predetermined objective criteria and additional vendor-related subjective criteria. The algorithm is based on calculating fuzzy suitability indices for the technically efficient robot alternatives, and then, ranking the fuzzy indices to select the best robot alternative. A comprehensive example is provided to illustrate the decision procedure. The algorithm proposed in here is also applicable to a broader area of decision problems, e.g. facility site selection, determination of the best CNC machine or flexible manufacturing system among a set of mutually exclusive alternatives.     

A finite capacity material requirements planning system

In a discrete parts manufacturing environment, material requirement planning (MRP) is carried out without considering the manufacturing resource capacity. As a result, during implementation, adjustments in planned orders may become necessary. This paper presents a finite capacity material requirements planning algorithm (FCMRP) to obtain capacity-based production plans. These plans need no costly adjustments to satisfy the capacity constraints. Performance of the FCMRP system, when studied through a set of test examples, has been found to be superior to the existing MRP system.     

Selection of methods,techniques and tools for system analysis and for the integration of CIM-elements in existing manufacturing organizations

Abstract

Implementation of computer-aided and integrated manufacturing systems requires one to consider all areas of the company in order to ensure a homogeneous and continuous evolutionary system development. Therefore, planners of computer integrated manufacturing (CIM) systems need a concept to come to a coherent selection of methods for those system development. In this paper a concept is introduced which allows an interdisciplinary team of system developers (engineers, industrial economists, personnel economists) a coherent choice of methods for system development. As examples, three methods applicable to the problem of CIM-implementation into organizations are evaluated.     

Production planning and inventory control in a company manufacturing PC parts: A case study

In this paper, we present a case study on the production planning and inventory system in a company manufacturing personal computer (PC) parts. In the case study, the targets are specified for developing a system for production planning and inventory control. The current state of the company is analysed for clarifying the points necessary to achieve the targets. Also, a system based on the analysis is proposed and its effects are estimated.     

A simulation study comparing performance of CONWIP and bottleneck-based release rules

Many firms seeking production economies and quicker throughput times have adopted cellular manufacturing techniques. New product introductions, increased product variety and process changes all add elements of uncertainty to the cell, and dynamic management techniques are required to achieve the benefits expected. This paper considers the problem of managing the flow of material into a manufacturing cell in order to maximize the output rate for a given level of work-inprocess inventory. The manufacturing cell is patterned after an Intel facility that assembles and tests microprocessors for the computer industry. The cell is studied under conditions in which a single bottleneck arises and those under which there are multiple bottlenecks. Alternative procedures for releasing material into the cell are evaluated in order to determine which offer the greatest advantage to managers.     

Decentralized WIP-oriented manufacturing control (DEWIP)

DEWIP is a manufacturing control system for job shop environments aiming at achieving short and reliable lead times by establishing WIP control loops between the manufacturing work centres. The paper describes the mode of function, the setting of parameters and simulation results of the new manufacturing control system. The setting of parameters is done with the aid of the funnel model and the theory of logistic operating curves, both developed at the Institute of Production Systems at the University of Hanover. The simulation is conducted using industrial data and makes it possible to assess DEWIP with regard to lead times, WIP level, performance and schedule reliability. DEWIP is compared both with an uncontrolled process and with the manufacturing control systems Load oriented order release (LOOR), Conwip and Polca. The results suggest that DEWIP and the models employed for the setting of parameters are suitable for job shop production and therefore offer a valuable alternative to prevailing centralized manufacturing control systems.     

Flexible reasoning using sensible agent-based systems: A case study in job flow scheduling

Planning and control systems for highly dynamic and uncertain manufacturing environments require adaptive flexibility and decision-making capabilities. Modern distributed manufacturing systems assess the utility of planning and executing solutions for both system goals (e.g. minimize manufacturing production time for all parts or minimize WIP) and local goals (e.g. expedite part A production schedule or maximize machine X utilization). Sensible Agents have the ability to alter their autonomy levels to choose among a set of decision models in order to handle the differences between local and system goals. In this paper, Sensible Agents are applied to a production planning and control problem in the context of job shop scheduling and decision model theory. Sensible Agents provide for trade-off reasoning mechanisms among system and local utilities that are flexible and responsive to an agent's abilities, situational context and position in the organizational structure of the system.     

Implementation of continuous flow manufacturing (CFM) system

In a world of global competition and demanding customers, putting production requirements ahead of customer's needs inevitably leads to manufacturing inefficiencies, higher inventories, and poor quality goods and services. In continuous flow manufacturing (CFM) system, the manufacturer makes how much and what is needed, and also when it is needed. A leading multinational company in oral care products produces toothbrushes through contract manufacturers (CMs). The contract manufacturer makes different stock-keeping units (SKUs) under two options: (i) the contract manufacturing option, in which CM supplies the finished products; (ii) the labour contract, in which CM is responsible only for conversion. Competitive pressure in the market pressures the company to change the operating system from the push system to CFM for CMs also. Moving from the push system with its high level of inventories to continuous flow manufacturing system enables the achievement of improved customer responsiveness, greater efficiencies, lower inventories and lower operating costs. This paper describes the way in which one such contract manufacturer was moved towards the CFM system and the benefits achieved through it.     

Experimental earliness/tardiness production planning with the due window system

In order to use the philosophy of JIT to improve the production planning method of MRP-II, we propose the experimental software system of the earliness/tardiness produc tion planning problem with due window. By means of the approaches and model reported in this paper, the optimal production planning can be achieved. The recommended model extends the problem of due window from the shop scheduling level into the aggregated planning level of mass manufacturing systems. Simulation results have demonstrated that the experimental software is a useful tool for the production management of repetitive manufacturing enterprises.     

Production planning and control tools

There are numerous tools available to be used for production planning and control purposes. The number of tools is ever increasing, and so are the levels of sophistication as well as complexity. For the specific manufacturing firm, the task of selecting the most appropriate set of tools is not trivial. However, in recent years, the understanding of the relationship between tools and manufacturing environments for which they are suitable has increased. The purpose of this paper is to provide an overview of production planning and control tools available today, as well as new trends, issues and ideas.