The paper describes the workings for four models of CONWIP systems used till date; the basic CONWIP system, the hybrid CONWIP system, the multi-product CONWIP system, and the parallel CONWIP system. The final novel model is introduced in this paper in a general form. These models may be adopted for analysis for both simulation studies and implementation on the shop floor. For each model, input ...

A high-mix, make-to-order production system can become inefficient when non-value added operations consume too much time, space or labour. To address these issues, cell re-layout is conducted and a CONWIP system is proposed. The cell re-layout started with data collection on current layout, product mix and routings, then the current layout was modified to develop several alternatives, and final...

Pull systems focusing on throughput time control and applicable in situations with high variety and customization are scarce. This paper compares pull systems that can cope with such situations: POLCA and CONWIP. Both systems constrain the maximum amount of work in progress (WIP) within a loop, but their effectiveness in terms of reducing total throughput time is questioned. They mainly differ ...

This article presents a simulation study over a small supply chain, where the amount of work-in-process (WIP) is restricted. The supply chain consists of five linked machines, or production facilities, with stochastic operation times. A number of test cases are made where the number of jobs in the machines and the buffer areas are restricted. The restrictions are designed both in the Kanban way...

Three types of JIT ordering systems used for supply chain management were quality tested, the Kanban, the original constant work-in-process (CONWIP), and a synchronized CONWIP. The synchronized CONWIP system is described for its ability to handle complicated supply chains, which consist of assembly stages with different lead times. In the system, orders for each process are released while adjus...

The control policy affects performance of a manufacturing line and can be classified as push, pull, or combination of pull and push. A pull or just-in-time (JIT) production system is a philosophy or an approach of the manufacturing system in which order release occurs due to physical removal of finished inventory in response to the customer demand. In this paper, we review the behavior of a man...

Despite technological progress and a large amount of research on Industry 4.0, digital transformation remains complex process that most manufacturers are hesitant to invest in. Interest in Kanban, for example, low compared with traditional which is widely used. This applies the other card-based production control systems, including CONstant Work-In-Process (CONWIP), focus this paper. In an indu...

Present study compares performance of proposed model [Hybrid Extended Kanban Control System (HEKCS)], with Extended Kanban Control System (EKCS) and Constant Work In Process (CONWIP) in a single line and multi stage manufacturing system with or without effect of machine breakdown. It was observed that, when demand rate increases, throughput, average WIP and utilization% also gradually increases...

In this paper we present CONLOAD CONstant LOAD a new lot release rule for wafer fabs It was developed to overcome some performance problems of traditional lot release rules like CONWIP or Work load Regulation during product mix changes We show that CONLOAD outperforms CONWIP and Workload Regulation with respect to keeping the bot tleneck utilization at a desired level and to provide a smooth ev...

In managing a production process, choosing a proper card-based control mechanism is an important task to achieve the best performance. We present performance evaluation of the three well-known card-based production control mechanisms, KANBAN, CONWIP and Base-stock in serial production lines. We employ the theory of token transaction systems within a deterministic framework. The performance meas...