A review of production planning and control: the applicability of key concepts to the make-to-order industry

The paper reviews ‘classic approaches’ to Production Planning and Control (PPC) such as Kanban, Manufacturing Resource Planning (MRP II) and Theory of Constrains (TOC), and elaborates upon the emergence of techniques such as Workload Control (WLC), Constant Work In Process (CONWIP), Paired cell Overlapping Loops of Cards with Authorization (POLCA) and web- or e-based Supply Chain Management (SCM) solutions. A critical assessment of the approaches from the point of view of various sectors of the Make-To-Order (MTO) Industry is presented. The paper considers factors such as the importance of the customer enquiry stage, company size, degree of customization and shop floor configuration and shows them to play a large role in the applicability of planning and control concepts. The paper heightens the awareness of researchers and practitioners to the PPC options, aids managerial system selection decision-making, and highlights the importance of a clear implementation strategy. WLC emerges as the most effective Job Shop solution; whilst for other configurations there are several alternatives depending on individual company characteristics and objectives. The paper outlines key areas for future research, including the need for empirical research into the use of Workload Control in small and medium sized MTO companies.     

A paradigm for ERP and BPR integration

In order to sustain a competitive edge in this global manufacturing era, enterprises need to adopt appropriate improvement schemes. Two widely-used tools have been Enterprise Resource Planning (ERP) and Business Process Reengineering (BPR). ERP is identified as the most applicable information system for the modern manufacturing industry. In addition, many BPR practitioners have identified the use of information technology (IT) as a critical factor for the success of BPR. Nevertheless, research into IT for BPR and hence ERP is limited. One of the major reasons why the ERP system has not been implemented successfully is the inappropriate use of design and implementation methodology employing the modern BPR concept. Accordingly, in this paper, the authors propose a conceptual model called the Hierarchical Design Pyramid (HDP), to implement ERP under an enterprise re-engineering (BPR) context, using an integrated structured and object-oriented tool to design a novel manufacturing system in a total quality environment. The proposed model aims to provide a basis for manufacturers to implement ERP in a systematic manner.     

Implementation of a demand-pull system in a job shop environment

This paper describes an implementation of JIT concepts in a medium-sized make-to-order manufacturing company. We develop a hybrid production control system for the company based on separating jobs with high production volumes following a standard routeing from relatively low-volume jobs with more complex routeings. The machines processing the high-volume standard-routeing jobs are treated as a virtual flow shop and controlled by a hybrid push/pull system, while the remainder of the floor is managed as a job shop. Initial tests have shown that this system can significantly improve throughput and simplify the production scheduling task. We believe that the system can be applied to a wide range of industries with similar characteristics. We also describe the testing of the system and the circumstances under which its implementation was discontinued, which indicate some of the difficulties faced by small manufacturers in implementing such systems.     

ERP research,development and implementation in China: an overview

An Enterprise Resource Planning (ERP) system is a highly integrated enterprise information system that manages all aspects of the business operations of an enterprise including production planning, purchasing, engineering design, manufacturing, marketing, distribution, accounting and customer service. In the last two decades, Manufacturing Resource Planning (MRP) and ERP have been successfully introduced into Chinese industry. Supported by sponsored research programmes, the research outcomes on ERP systems by Chinese academic researchers have been directly supporting the Chinese ERP software industry. An overview of ERP research and its development and implementation in China will be given here. The research trend of ERP systems will also be discussed.     

Extended structured adaptive supervisory control model of shop floor controls for an e-Manufacturing system

The high cost and long development cycle of shop floor control systems and the lack of true system integration capabilities are identified as one of the most challenging obstacles in deploying e-Manufacturing systems. Overcoming these obstacles is essential for manufacturers to execute a make-to-order business model in order to stay competitive and remain profitable in the future. We propose a formal method to generate the desired control trajectories and provide true integration mechanisms for shop floor control systems. Using the proposed architecture can result in the development of an e-Manufacturing system capable of achieving a substantial reduction of both the high cost and long development cycle currently required to engineer shop floor control systems. By taking advantage of both the linear growth of the complexity function in a structured adaptive supervisory control model and the information-centric characteristics of a virtual production line in a manufacturing execution system, a formal model, which we call an extended structured adaptive supervisory control, for a discrete manufacturing system is introduced. A shop floor control system based on the extended structured adaptive supervisory control model is built for an industrial testbed system. The shop floor control system is fully tested and evaluated.     

制造业车间作业计划与调度研究

基于车间作业计划( Production Activity Control,PAC)是企业生产计划的最终环节,且其对制造领域里的经营管理效率起着支撑作用,因此针对当前企业存在的诸多问题,在系统分析了作业的特点以及对PAC编制的来源及过程的总结基础上,科学地归纳出制造业领域的车间作业计划(PAC)与调度流程,并给出了相应...     

Agile manufacturing: Enablers and an implementation framework

Tougher competitive situations have led to increasing attention being paid to customer satisfaction, of which timely and customized services are the key concepts. As the product life cycle becomes shortened, high product quality becomes necessary for survival. Markets become highly diversified and global, and continuous and unexpected change become the key factors for success. The need for a method of rapidly and cost-effectively developing products, production facilities and supporting software, including design, process planning and shop floor control system has led to the concept of agile manufacturing. Agile manufacturing can be defined as the capability to survive and prosper in a competitive environment of continuous and unpredictable change by reacting quickly and effectively to changing markets, driven by customer-designed products and services. This article details the key concepts and enablers of agile manufacturing. The key enablers of agile manufacturing include: (i) virtual enterprise formation tools/metrics; (ii) physically distributed manufacturing architecture and teams; (iii) rapid partnership formation tools/metrics; (iv) concurrent engineering; (v) integrated product/production/business information system; (vi) rapid prototyping tools; and (vii) electronic commerce. A conceptual framework for the development of an agile manufacturing system and future research directions are presented in this paper. This framework takes into account the customization and system integration with the help of business process redesign, legal issues, concurrent engineering, computer-integrated manufacturing, cost management, total quality management and information technology.     

Supervisory control and data acquisition for virtual enterprise

The new manufacturing paradigms, such as agile manufacture and lean production, are leading industrial countries towards the new generation of concurrent enterprises involving virtual enterprise architecture and concurrent engineering extended methodology. Continuing adaptation to the market can only be achieved efficiently if the planning and control processes are both optimized horizontally (Automatic Control Systems) and vertically (Management Control Systems). The desired improvement in performance and the realization of global enterprise objectives require a tight integration of the units of the enterprise. The close monitoring of the operational performance of various plants, manufacturing shop-floors/cells/machines, as well as their associated instrumentation and control is of increasing strategic importance. Failures can lead to increased costs and reduced product quality, consistency and production, and to plant shutdowns and increased environmental impact. There is a real need for advanced monitoring technologies to be applied, and their potential demonstrated, on complex industrial plants. The planning and scheduling of manufacturing systems integrated into virtual enterprise architectures requires the implementation of new General Master Production Planning and Scheduling techniques and Supervisory Control and Data Acquisition (SCADA) functions. This paper discusses some key issues on the SCADA-oriented open system for virtual enterprise architecture.     

Design of POLCA material control systems

POLCA is a material control system designed for make-to-order or engineer-to-order companies. These firms have to cope with a high variety of customised products, and strong pressure to provide short throughput times. POLCA constrains the amount of work in progress on the shop floor in order to achieve a short average shop floor throughput time. Earlier work has shown that the POLCA system has the capability to reduce both the average shop floor throughput time and the average total throughput time, but it is only effective if the POLCA system has been appropriately designed. The design of the POLCA system is therefore being investigated and discussed in this paper. We give an extensive literature review and give attention to the authorisation mechanisms of POLCA, the design of control loops, the route-specific capacity signals (POLCA cards), and specific facilities needed to use the POLCA system in practice. Finally, we report on the design of a POLCA system in practice, the first complete implementation of POLCA in The Netherlands, and present the quick scan that was used in the design of the POLCA system for this SME.     

Negotiating price/delivery date in a stochastic manufacturing environment

We study a make-to-order manufacturing system consisting of several processing centers that are subject to failures and repairs. Our objective is to build a model that can be used as a tool for negotiating the delivery date and the price of a certain upcoming order. The model takes into account the congestion level of the shop floor at the time the order is placed. Based on the workload of the processing centers, the model splits the order into lots and assigns them to the processing centers so as to determine the order completion time associated with the minimum operating cost. The efficiency of the solution method for the model allows real-time decision-making while negotiating the price and delivery date of the order to be placed. Since the decisions are made based on a snapshot of the congestion level at the shop floor, using this model will reduce the conflict between the marketing and the production activities in manufacturing organizations.     

DOPP—dynamically optimized production planning†

Production planning in flexible manufacturing requires the updating of work schedules each time a new product order is acquired. To this end, a Production Planning (PP) strategy should be devised by solving two coupled problems, embedded into an iteration: (i) Product Orders Scheduling, (ii) Production Capacity Planning. This paper presents a new algorithm to solve the Production Capacity Planning (PCP) Problem for a complex manufacturing system composed of a network of bufferized time-sharing workshops (i.e. shops able to share their service rates among different part types). The solution procedure developed allows one to minimize the Global Flow Time (GFT), while verifying service and storage capacity constraints, in association with a given future pattern of product orders. An example derived from an existing production process is outlined, to show the effective usefulness of the proposed PCP procedure, and its easy integration with existing scheduling tools     

Integrative process plan model and representation for intelligent distributed manufacturing planning

Process planning is one of the key functions for product design and manufacturing. Process plans have very great impact on all phases of product design and manufacture. Therefore, it is necessary to establish a high level of interaction between different product design activities and their tight integration into a coherent system. In this paper we describe a process plan model that allows for such integration. The framework for integration is briefly described and the process plan model that considers three dimensions of planning is explained. The manufacturing process plan model is defined as a three-dimensional model with the following dimensions: time/order, variability/alternatives, and aggregation. All three dimensions are defined and explained as they relate to overall manufacturing planning. The nature of these dimensions is illustrated with several examples. The implementation of the framework and the model within the distributed system IMPlanner is presented. The prototype has been implemented in the Java language and the model for data storage has been implemented in XML. The benefits of integrated consideration are described for several currently implemented applications such as feature modelling, process visualization, process network generation, cell formation, and scheduling.     

Reducing feedback requirements of workload control

The workload control concept is known as a robust shop floor control concept. It is especially suited for the dynamic environment of small- and medium-sized enterprises (SMEs) within the make-to-order sector. Before orders are released to the shop floor, they are collected in an ‘order pool’. To make the release decision, information regarding the actual situation on the shop floor is required. Within SMEs, this information is often incomplete, incorrect or delayed. However, the workload control approaches discussed in the literature assume precise feedback information. The paper discusses the opportunities for information feedback from the shop floor for centralized order release within SMEs and analyses the information requirements of workload control approaches. These approaches are adapted based on more realistic assumptions regarding information supply within SMEs. The different approaches are compared and assessed by a simulation study. Results show that additional investments in more accurate information supply lead to decreasing marginal improvements in overall shop performance. Additionally, they indicate that the choice of the right workload control approach might have important effects on performance.     

Improving the path to align sales,production planning and engineering in high-variety versatile environment

Versatile manufacturing companies typically manufacture high variety, mainly customized products in relatively low volumes, competing for each order with other supplier companies on the basis of price, technical expertise, delivery time and punctuality. In this environment, the combination of high variety and frequent product changes/modifications entangles planning, designing, purchasing and manufacturing activities, thus exacerbating the conciliation of the contrasting goals of Sales, Production Planning and Engineering. This paper aims to explain how planning bills—traditionally adopted to coordinate Sales and Production Planning—can be used to improve alignment among these functional areas in a versatile manufacturing context. In particular, a path is proposed to align not only Sales and Production Planning requests, but also those of the Engineering function. Interestingly enough, such an approach is particularly suited to cope with the frequent product changes characterizing a high-variety versatile environment, and makes it possible to achieve greater advantages than those conventionally attributed to the planning bills.     

DESIGN OF A KNOWLEDGE-BASED ON-LINE SIMULATION SYSTEM TO CONTROL A MANUFACTURING SHOP FLOOR

In this paper, the design principles of a new knowledge-based on-line simulation (KBOLS) architecture for the purpose of integrating the supervisory decision making process with a shop floor control system is discussed. The requirements for implementing the KBOLS architecture in a computer integrated manufacturing environment are presented. The special features of the KBOLS architecture include a knowledge-based controller capable of interacting with the shop floor and a manufacturing simulator, a shared blackboard data structure for knowledge bases, and a learning module. The KBOLS architecture is implemented in a flexible manufacturing system for analyzing interruptions due to machine breakdowns and rush orders.     

面向用户的CAPP系统开发技术研究与实践

分析了面向用户的ＣＡＰＰ系统开发需求,提出了基于工艺卡片模板和工艺信息对象模型的工艺文件数据结构,阐述了实现信息集成的系统功能,给出了实用化工艺设计方法,论述了基于ＡｃｔｉｖｅＸ的软件开发技术。基于上述研究开发的面向用户的ＣＡＰＰ系统已投入实际应用,并取得了良好效果。     

The design of business processes within manufacturing systems management

Manufacturing organizations are currently being subjected to increased business, regulatory and legislative pressures that require them to regularly re-engineer themselves. To be able to effectively manage such activities, a manufacturing systems management (MSM) framework is required, which helps to define the necessary activities needed to regulate and optimize a manufacturing system as it progresses through its life cycle. The current merging of automotive manufacturers highlights the need for such a framework. Maximizing the benefits of such mergers requires the effective convergence of the organizations' processes, which is a complex undertaking that requires a structured approach. Through an approach known as Business Process Development (BPD), as used in the case of the design of BMW's new UK engine factory, this paper describes how a MSM framework can be applied in practice to deal with a range of issues related to the analysis, design and implementation of a new manufacturing system.     

Research on rush order insertion rescheduling problem under hybrid flow shop based on NSGA-III

Rush order insertion is widespread in the enterprises that apply make-to-order production mode which affects the stability of production system. This article studies rush order insertion rescheduling problem (ROIRP) under hybrid flow shop (HFS) with multiple stages and multiple machines. A mathematical model simultaneously considering constraints such as lots, sequence-dependent set-up times and transportation times with objectives to minimise makespan, total transportation time and total machine deviation between the initial scheduling plan and the event-driven rescheduling plan is developed and NSGA-III is applied to solve the problem. Three groups of experiments are carried out which verify the suitability of NSGA-III for HFS scheduling problem with multi-objective and multi-constraint, the effectiveness of NSGA-III for the proposed ROIRP and the feasibility and effectiveness of the proposed model and algorithm in solving the ROIRP of a realistic ship pipe parts manufacturing enterprise.     

Extending capacity planning by positive lead times and optional overtime,earliness and tardiness for effective master production scheduling

In this paper we consider the problem of improving the Master Production Schedule (MPS) in make-to-order production systems when demand exceeds available resource capacity. Due to the complexity of the problem, in practice solutions are usually obtained manually. We propose an algorithm that offsets production orders guided by tardiness, earliness and overtime penalties. The intermediate tool used to determine resource utilization is Rough Cut Capacity Planning (RCCP) extended by positive lead times and options for overtime, earliness and tardiness. This approach leads to a more realistic resource loading calculation, similar to CRP but without its computational burden. The discrete optimization model is solved by a Genetic Algorithm (GA); within the GA, delays or early deliveries of each order are represented as genes of a chromosome. The method is tested against systematically developed benchmark problems and real industrial data. Improvements over the traditional RCCP procedure and an ERP's embedded routines are demonstrated by the computational results and support the applicability of the proposed approach for real-life make-to-order environments.