Industrial design and simulation of a JIT material handling system

Abstract

A Just-in-Time (JIT) Material Handling System attempts to manufacture products from start to finish by rearranging the factory floor layout away from batch production toward a product layout using flow lines. One of the most accepted JIT production methods used in this work is known as the Kanban system. Kanbans are used to operate a pull system of material control that links all supplying operations to a final assembly line. The ultimate goal of this system is the conversion of raw materials at the Juhel Oral Drug Process plant into finished products with lead time equal to processing time. The flows in the manufacturing model include: the flow of materials, the flow of information, and the flow of cost. These flows create the value streams. Components of the value stream can be value-add or waste, depending on the operating conditions. The simulation model developed in this research work is based on the single-card pull system developed at the Drug Process Plant. This model consists of three blocks (workstations) where there is a buffer located between two workstations. In this model, the material moves according to the Kanban rule. If Kanbans arrive and the material is available, the workstation starts processing the material. This research demonstrates that the design of the JIT system can significantly affect key manufacturing performance measures. JIT implementation cannot provide significant benefits if setup time and variability remain high as well as if the company is not able to optimise the production facilities by product mix. Based on the result from this work, JIT is not based upon rigid concepts. Therefore, successful implementation depends largely on the company’s ability to identify problems, creativity and efforts. The application of single-card pull system coupled with the use of the trigger point results in simpler mechanisms for operating the system.

Keywords:

• Kanban system
• system flows
• pull mechanisms
• trigger point
• entity flows

Public Interest Statement

A Just-in-Time (JIT) Material Handling System works on a demand-pull basis, all goods made would be sold, and thus it incorporates changes in demand with surprising ease. This makes it especially appealing today, where the market demand is volatile and somewhat unpredictable. JIT manufacturing mechanisms presented in this paper encourages the “right first time” concept, so that inspection costs and cost of rework is minimized. High quality products and greater efficiency can be derived from following a just-in-time production system. Close relationships are fostered along the production chain under a just-in-time manufacturing system. Constant communication with the customer results in high customer satisfaction. Overproduction is eliminated when JIT manufacturing is adopted. The results show that in a JIT-Kanban based production system, the finished product demand (D_F) is a vital factor and establish the on-hand inventory, especially when finished product demand shifts significantly influence the overall inventory cost. The research work will be beneficial to all manufacturing organizations including small scale business and large corporations.

Additional information

Funding

Funding. The authors received no direct funding for this research.

Notes on contributors

Chukwuedozie N. Ezema

Chukwuedozie N. Ezema is a PhD student at the Department of Electronic & Computer Engineering, Nnamdi Azikiwe University, Nigeria. He received his Bachelor of Engineering Degree and Masters Degree in Electrical & Electronic Engineering from Anambra State University, Nigeria. He also holds a Bachelor of Engineering Degree in Mechanical & Production Engineering from Nnamdi Azikiwe University, Nigeria and another Masters Degree in Information Technology.

Eric C. Okafor

Eric C. Okafor is a professor at the Department of Computer Engineering, Enugu State University of Science & Technology, Nigeria. He received his Bachelor Degree in Electrical & Electronic Engineering from Anambra State University of Technology, Enugu, Nigeria. He received his Master’s Degree in Digital Systems & Computer Engineering and PhD in Computer Engineering from University of Nigeria, Nsukka.

Christiana C. Okezie

Christiana C. Okezie is a professor at the Department of Electronic & Computer Engineering, Nnamdi Azikiwe University, Awka, Nigeria. She holds a Bachelor Degree in Electrical/Electronic & Computer Engineering. She also holds Master’s Degree and PhD in Computer Engineering.