Integrated Production Control Research Articles

Integrated Capacity Planning and Production Control of an Assembly Manufacturing System

For an assembly manufacturing system, its capacity planning problem and production control problem are usually considered separately. However, production capacity cannot exert its maximum productivity without employing optimal production control; and optimal production control may not satisfy the demand without sufficient production capacity. Therefore, it is important to jointly optimize capacity planning and production control. First, the mathematical formulation of integrated production control and capacity planning problem for an assembly manufacturing system with multiple upstream production lines and one downstream assembly line is proposed in this paper. Second, we develop a method to obtain the marginal probability distribution of the inventory level in the assembly system, which can be employed to calculate the average production cost under an approximate optimal production control policy. Since optimal control policy is subject to production capacity (i.e., machine number), we employ the integer programming method to optimize the machine number (i.e., production capacity), which consequently influences the control policy. Numerical experiments are conducted to verify the correctness of the method of calculating steady-state probability distribution, and the effectiveness of the algorithm of integrated optimization of production control and production capacity.

Dynamic method to identify and analyze waste by making-do in construction sites

Abstract: The study of making-do contributes to improvements in the planning and control of construction sites, thus minimizing waste. The present study aims to investigate and analyze waste by making-do in seven companies from Goiás with the aid of a Dashboard and perform the risk analysis of the identified waste. Data were analyzed during the technical visits at each site, among which the direct non-participant observation, questionnaire application and document analysis stand out. The analysis of the data indicated that most of the waste is related to the steps of sealing and structure within the construction sites, in particular, for components connected to plastering and concreting. The main impact was rework, followed by reduced security. With the risk analysis, the main points were identified according to their severity, thus guiding management decision making. As final contributions, the main impacts and suggestions for their minimization are presented. Therefore, we highlight the need to use reality and information technology tools in future works for integrated production control and to assist in the identification of waste by making-do in construction sites.

Integrating Production Control and Scheduling in Multisite Enterprises on the Basis of Real-Time Detection of Divergence

Scheduling and process control have been long recognized as the two critical building blocks in many manufacturing execution systems. Operating at the interface between the supply chain and the process, the scheduler generates a detailed schedule that has to be executed by the process so as to meet the demands originating from the supply chain. Given the tight interactions between the two, there has been wide interest in integrating scheduling and process control. Our key insight is that abnormalities which occur after generation of the original schedule trigger a divergence between the operational targets defined by the schedule and its execution. If left uncorrected, then the abnormalities will propagate between the process and the supply chain. A timely response could eliminate or minimize such effects. However, this is a challenge particularly in large multisite enterprises where the scheduling and production responsibilities are typically separated across departments and even across geographical loca...

Advanced Control in a Delayed Coking Furnace

This article reports an industrial application of advanced control in a delayed coking furnace unit. The advanced control is required because of the semi-batch and semi-continuous nature of the unit. The traditional proportional–integral–derivative control has been proven not sufficient and capable for this particular petro-chemical process. The advanced control is formed by integrating a predictive functional controller with a traditional proportional–integral–derivative controller in cascade architecture with a feed-forward compensator designated for disturbance rejection. The advanced control system is implemented in a Yokogawa CS3000 integrated production control system. The application results indicate that the advanced control can significantly improve the performance of the delayed coking furnace unit in terms of the outlet temperature of furnace and oxygen concentration of the chimney.

A model-driven approach to enabling change capability in SMEs

To sustain competitive performance in dynamic business, technical, economic and social environments, change capability is an essential characteristic property of any small- to medium-sized enterprise (SME). It follows that the business, engineering and production systems deployed by SMEs must be transformable, reconfigurable and interoperable. Likewise the models we deploy to engineer, change and operate SME systems must themselves be transformable, reconfigurable and interoperable. This paper reports on the application of new modelling concepts and modelling methods that are designed to facilitate change capability in SMEs. ‘Role’ and ‘resource’ modelling concepts are used in complementary forms to describe the ‘how’ and ‘who’ of SME systems in such ways that inherent complexities and change requirements can be faced by managers and engineers responsible for the life cycle engineering of SMEs. With respect to ‘role’ modelling the paper describes how an extension of standard enterprise modelling techniques can enable the decomposition and formal multi-level of abstraction description of sets of process-oriented roles; such as those required in any specific SME case to realise changing products and services for customers. Regarding resource modelling the paper describes how the ‘Dynamic Producer Unit’ (DPU) concept enables decomposition and multi-level of abstraction description of people, machine and IT system elements in a coherent manner. The paper goes on to describe a novel method of applying ‘role’ and ‘DPU’ concepts. This novel method takes the form of an ‘Integrated Production Control Modelling Approach’ and a support ‘Simulator’. By being based upon ‘role’ and ‘DPU’ modelling concepts the ‘coherent and flexibly integrated’ use of static enterprise models, causal loop models, simulation models and workflow models is facilitated. Finally, the paper exemplifies the use of the IPCMA and IPCMS with reference to the changing requirements and systems of an SME making many types of furniture product with a common set of resources.

Reconfigurable Integrated Production Control System of industrial processes on QNX Neutrino platform

This paper presents the structure and implementation of the Integrated Reconfigurable Production Control System. The solution offers monitoring, control and supervision of manufacturing systems equipped with Enterprise Resource Planning (ERP) and Supervisory Control and Data Acquisition (SCADA) systems. The article proposes the architecture and the main principles of such a system, as well as its substantive tasks. QNX Neutrino system was chosen for a development platform as it provides real-time operations for control loops. The proposed project is intended for continuous industrial production systems.

A proposal for integrating production control and quality control

PurposeThe purpose of this paper is to present a practical proposal for integrating production control (PC) and quality control (QC) at the shop floor level.Design/methodology/approachThe proposed method is based on three principles which relate PC and QC at the shop floor level. The proposal is applied successfully at the world's largest pencil factory.FindingsThe results show that the proposed method contributes to improve four performance indicators related to PC and QC at the company studied: increase the average throughput in about 28.9 per cent; reduce the average value of work in process (WIP) in about 35.6 per cent, reduce the average lead time by about 45.4 per cent, and reduce the average defect rate by about 71.4 per cent.Research limitations/implicationsThe proposal (mainly because of principle III) is developed to be applied in repetitive production (RP) systems, i.e. environments characterized by low production volume and low product variety.Practical implicationsSome practical implications for industrial managers arises from this study: managers must consider the importance of integrated PC and QC functions in order to get better results concerning performance indicators such as throughput, WIP, lead time, and rejection rate; the materials flow simplification is a prerequisite for a lot of improvement initiatives at the shop floor level; the adequate choice of the production control system (PCS) is vital in order to get positive results regarding the performance indicators related to PC; the determination of the production pace (or rate) for a RP system must take account capacity restrictions and the influence of defect rate on production rate.Originality/valueThe paper is original in that it shows that the performance of the shop floor level can be improved by means of integrating PC and QC, by discussing and implementing a method which simplifies the material flow in the shop floor level, chooses the most adequate PCS and shows how the production rate influence on the rejection rate. Therefore, the paper is important for those which practice industrial management, more specifically on PC and QC functions.

Development of integrated production control system for electric arc furnace process

Development of integrated production control system for electric arc furnace process

Design and Implementation of Integrated Production Control Systems

There has been much discussion on the merits of different production control philosophies, particularly MRPII, OPT and JIT. A consensus is emerging that these philosophies are not mutually exclusive, and some companies are beginning to mix and match different approaches to meet their particular needs. The design of hybrid production control systems requires the establishment of a theory of production control that embraces, but is independent of, the well‐defined philosophies of MRPII, OPT and JIT. Without such an understanding of production control there is no framework within which to build hybrid production control systems. Five universal principles of production control are set out, and it is shown how these principles can be used to construct the Integrated Production Control (IPC) Model. This model provides the conceptual framework necessary for the design of hybrid production control systems. The relationships of MRPII, OPT, and kanban, the classical JIT scheduling system, are explored, and areas of strength and weakness identified.

Yield model for in-line integrated circuit production control : S. Simitrijev, N. Stojadinovic and Z. Stamenkovic. Solid-St. Electron.31, 975 (1988)

Yield model for in-line integrated circuit production control : S. Simitrijev, N. Stojadinovic and Z. Stamenkovic. Solid-St. Electron.31, 975 (1988)

Yield model for in-line integrated circuit production control

A yield model suited for application in yield control system of integrated circuit production has been proposed. It is based on in-line inspections made on a control wafer containing corresponding test structures. The yield model gives mean and variance of wafer yield associated with each critical process step as well as the complete distribution function of final wafer yield. The model is illustrated by modeling of yield concerning production of well-known CD4000B series CMOS integrated circuits.

Design of Integrated Production Control Systems for the Paper and Board Industry

This paper outlines new development in the design of Decision Support Systems and Mill Wide control. These developments have been implemented .in a system for a board mill at Thames Purfleet whose management worked closely with the university based Systems Group at Imperial College. The system design to control a multiproduct plant producing a range of reels, sheet and board in various dimensions, consistency, colour and surface finish. It uses advanced procedures for scheduling, deckling, sales forecasting and stock control and employs an advanced “what-if” evolutionary simulation for prediction, management decision support and production control via a terminal network. The system has rapid “conversational” response.

An integrated production control in power systems

The main objective of production control in power systems is to minimize the cost of generated power while maintaining its quality at a high level and satisfying the system security constraints. Keeping voltages at predetermined levels and keeping constant net frequency are understood as the quality of delivered power. These objectives are accomplished by several application functions in a real-time computer control system. A novel design concept integrating the economic dispatch calculation (EDC), automatic generation control (AGC) and load prediction functions in an interacting control scheme is described in this paper. An adaptive control procedure for the overall system results from this approach. Variations of the power demand are better matched in this way. Increased computational capacity during periods of slow variations of the power demand is one of the benefits of this approach.

Current developments in computer hierarchies for industrial control

The paper reviews the present trends in the use of computers for process control through the combined experiences of the activities of the authors' organizations in the field. Examples quoted showing the wide range of application which has to be covered include integrated production control, hierarchical control and direct digital control. Conclusions are drawn about the effect which the requirements will have on the design of suitable equipment in the next few years.

The spread of computer control in steel mills

The application of digital computers in the metals industry has experienced an extremely rapid growth over the past five years, both in this country and in Europe. Indicative of this trend is the fact that the six new continuous hot strip mills most recently built, or being built, in the United States were all designed for and purchased with process computer control. The typical functions in such systems include reheat furnace control, slab tracking, roughing and finishing mill setup, finishing and coiling temperature control, and production logging. Other more recent applications have been made in the steel making and primary mills area, both of which have found ready acceptance. Results from early applications now available indicate that projected economic justification in terms of quality improvement is valid. Several in-service installations are described and the results obtained are discussed. Examination of the steel industry processes leads to a belief that, over the next decade, almost all parts of the steel plant will be computer-controlled. This continuing growth will be limited only by our ability to understand and rationalize the process to be controlled. Presently on the horizon is overall control of the steel plant from customer order to product shipment. Multiple computers, both business and process control, will be linked together to achieve integrated production control throughout the production cycle. The results will be improved efficiency of operation and shortened delivery cycle time.

Computer control of steelworks production

The paper describes the application of integrated production control using three computers to the Rotherham works of the Park Gate Iron and Steel Co. Ltd. The system, installed to meet the needs of a considerably expanded steelworks, will come into service early in 1964.Offline production-planning facilities cover operations from the steelmaking plant to the finishing mills, but online production co-ordination is restricted to the primary-mill area through which all products must pass. Process controls are applied as automatic programming of the bloom mill and computer control of the billet flying shear.The production-planning computer receives incoming orders and feedback data from the works. It updates the appropriate magnetic-tape files and issues working schedules to the various departments.Primary-mill instructions are issued as paper-tape input to the co-ordination computer. Here ingots are identified with orders, and processing instructions are relayed to operators on a tabular display system and by direct links to the automatic mill programmer and the shearing computer.The shear-computer system measures ingoing length, predicts outgoing length and directs billet cutting for minimum waste. It also tracks and identifies the cut billets on the cooling bank.