Comparison Of Parallel Kanban-Base Stock System To Control Multi-Product Multi-Stage Production With Rework Through Simulation

A recent globalization challenge compels manufacturing industries to offer a large variety of products with varied demands to suit their customers’ needs. However, these complex scenarios have led to high work-in-process (WIP) and defects, thus inspires many researches to investigate the optimum ways to manage this complex manufacturing system within the scope of production control system (PCS). Most research in PCS has previously focused on the ideal production system and rework is seldom being considered.This study aims to develop and to evaluate the performance of a new hybrid PCS known as Parallel Kanban-Base stock (PKB) system to regulate a multi-product multi-stage production with the entrance of rework. In contrast to the original hybrid kanban-base stock system, PKB system takes into account of three variants. First variant are two classes of the product families known as high-runner (HR) and low-runner (LR) based on the demand of the product mix. The second variant is the variations of dispatch rules to regulate product families categorized as high runner-low runner (HL) and low runner-high runner (LH). Third variant considered was two rework entrance policies classified as merge (MR) and original (OR). The studied systemshave been modeled using discrete-event simulation. The simulation results are analyzed based on statistical methods including analysis of variance, regression and response surface methodology. The selection of related parameters, variables and performance measures is relatively based on literature study and current practice of a case study company. This study has been divided into three cases. For Case 1, among rework entrance policies, predominantly MR rework entrance policy yields more desirable results as observed within the performance measures, compared to OR rework entrance policy. For Case 2, the results revealed that PKB system with different customer demands shows HL dispatch rule is superior to LH dispatch rule. For Case 3, PKB-HL-MR gives the optimum results compared to other models. Overall findings show that PKB system possesses the advantage of a Base stock System (for LR) by causing an approximately 1.3% higher total output and the advantage of a Kanban System (for HR) by having controllable WIP levels. Significantly, this research contributes to the knowledge in the area of PCS in multi-product multi-stage environment considering reworking process.For future research, this work can be extended to the analysis of more complicated system configurations such as a machine breakdownand run the simulation model for various types of industries

Introduction to Production: Philosophies, Flow, and Analysis

Production is a fundamental societal and economic activity. Production has to do with the transformation of raw materials into useful objects and includes the knowledge to complete the transformation effectively. Thus, production is a board topic ranging from philosophies about how to approach production such as lean and quick response manufacturing, how to organize production facilities, how to analyze production operations, how to control the flow of materials during production, the devices used to move materials within a facility, and strategies for coordinating multiple production facilities. An integrated introduction to production is presented in a set of learning modules. In significant part, these learning modules are based on over 20 years of interactions with the professional production community in the West Michigan region where Grand Rapids and Holland are the principal cities. This community consists almost exclusively of small and medium size companies engaged primarily in high mix, low volume manufacturing. Students in the Bachelor of Science in Engineering and Master of Science in Engineering programs at Grand Valley State University often work in production for these companies. Thus, interactions are facilitated particularly though master’s degree capstone projects, several of which are referenced in the learning modules. The learning modules are well-grounded in established production concepts. Emphasis is placed on proven procedures such as systematic layout planning, factory physics, various production flow control techniques such as kanban and POLCA, and discrete event simulation. Professional practice is a focus of the learning modules. Material from processional groups such as the Lean Enterprise Institute and the Material Handling Institute (MHI) is integrated. The opportunity to read and discuss professional publications presenting production improvement projects is provided. Students are referred to professional videos and web sites throughout the learning modules. All materials provided are referenced are open access and free of charge. When downloading the main file, it is important to also download and use the Main File Support as it contains supplemental materials.https://scholarworks.gvsu.edu/books/1022/thumbnail.jp

Application of lean scheduling and production control in non-repetitive manufacturing systems using intelligent agent decision support

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Lean Manufacturing (LM) is widely accepted as a world-class manufacturing paradigm, its currency and superiority are manifested in numerous recent success stories. Most lean tools including Just-in-Time (JIT) were designed for repetitive serial production systems. This resulted in a substantial stream of research which dismissed a priori the suitability of LM for non-repetitive non-serial job-shops. The extension of LM into non-repetitive production systems is opposed on the basis of the sheer complexity of applying JIT pull production control in non-repetitive systems fabricating a high variety of products. However, the application of LM in job-shops is not unexplored. Studies proposing the extension of leanness into non-repetitive production systems have promoted the modification of pull control mechanisms or reconfiguration of job-shops into cellular manufacturing systems. This thesis sought to address the shortcomings of the aforementioned approaches. The contribution of this thesis to knowledge in the field of production and operations management is threefold: Firstly, a Multi-Agent System (MAS) is designed to directly apply pull production control to a good approximation of a real-life job-shop. The scale and complexity of the developed MAS prove that the application of pull production control in non-repetitive manufacturing systems is challenging, perplex and laborious. Secondly, the thesis examines three pull production control mechanisms namely, Kanban, Base Stock and Constant Work-in-Process (CONWIP) which it enhances so as to prevent system deadlocks, an issue largely unaddressed in the relevant literature. Having successfully tested the transferability of pull production control to non-repetitive manufacturing, the third contribution of this thesis is that it uses experimental and empirical data to examine the impact of pull production control on job-shop performance. The thesis identifies issues resulting from the application of pull control in job-shops which have implications for industry practice and concludes by outlining further research that can be undertaken in this direction

Facilities Redesign of Stockroom at Elcon Precision

Elcon Precision is a company based out of San Jose, California specializing in the photochemical processing of materials and brazing of metals and ceramics for a variety of different industries. Three students from the Industrial Engineering Department at California Polytechnic State University, San Luis Obispo were contacted by Elcon Precision to help redesign their stockroom and inventory areas in their San Jose location in order to allow for the future growth of the company. Elcon asked the Cal Poly project team to help increase efficiencies throughout the stockroom by creating an alternative layout that best suited the company\u27s needs. This report will provide an in depth analysis of the Cal Poly project team\u27s approach to achieve a more efficient layout for the Elcon Precision stockroom

Production Operations Level: Transition-To-Lean Roadmap

This paper provides a roadmap for transitioning an existing production operation to one that fully implements a lean manufacturing philosophy. Integration of engineering, human resources, and business viewpoints are incorporated into the roadmap to provide a systematic implementation process. Specific actions, in order of precedence, are organized into major phases with points of interface defined with other systems that are both internal and external to the business enterprise. Definitions of those terms used on the roadmap, which are unique in describing lean activities and practices, are also presented in this paper. The roadmap is based upon experience gained to date by members of the Lean Aerospace Initiative in implementing lean philosophy into production operations at various aerospace facilities and validated by research conducted by this consortium at the Massachusetts Institute of Technology

Improving the efficiency of an automated manufacturing system through a tri-part approach

Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 71-72).This research investigates a complex automated manufacturing system at three levels to improve its efficiency. In the system there are parallel loops of stations connected by a single closed conveyor. In each loop there are a series of identical stations, each with multiple storage slots and with capability to process several jobs simultaneously. At the system level we undertake capacity planning and explore Work-in-Process (WIP) control. We build an Excel model to calculate the implied load of each station, applying the model to sensitivity analyses of the system capacity. In addition, we identify a concave relationship between output and WIP based on actual factory data from our industrial partner. We surprisingly observe a reduction in output when WIP is high. Therefore, we suggest adopting a CONWIP policy in the system in order to increase and smooth the output. At the loop level we study the assignment policy. The complexity of this study is highlighted by non-trivial travel time between stations. We build a simulation model in Matlab to compare different assignment policies. The objective is to find the assignment policy that balances the station load, decreases the flow time for jobs, and reduces the rejection or blockage rate for the system. At the station level we investigate the holding time between simultaneous processes. We model this as a semi-Markov process, building a simulation model in Matlab to confirm the analytical results. We discover a tradeoff between flow time and production rate with different holding times, and propose new holding rules to further improve station performance. The conclusions from this research are useful for our industrial partner in its efforts to improve the operation of the system and to increase its capacity. Moreover, the methodologies and insights of this work can be beneficial to further research on related industry practice.by Chen Song.S.M

Summary of Research Conducted by the Manufacturing Systems Team 1994-2002

The Manufacturing Systems team was one of the research teams within the Lean Aerospace Initiative (LAI) whose goal was to document, analyze and communicate the design attributes and relationships that lead to significant performance improvements in manufacturing systems in the defense aerospace industry. This report will provide an integrated record of this research using the Production Operations Transition to Lean Roadmap as its organizing framework

Comparison and optimization of control policies in automobile manufacturing systems by simulation

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (p. 109-110).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.This thesis studies material flow control policies for automobile manufacturing systems. Various control policies are implemented in simulations of manufacturing systems to test whether they increase the efficiencies of the systems in terms of specific performance measures of interest. Among the control policies, Control Point Policy (CPP) is deeply studied, because this policy is designed for controlling complex manufacturing system with multiple product types. First, fundamental research in CPP is presented to understand the effects of the parameters on single product type manufacturing systems. Then, multiple product type, assembly-disassembly systems are studied with various control policies, including hybrid policies. Finally, a real automobile manufacturing system case study is presented, and various control policies are experimented on in the simulation model. Because the evaluations of performances are done by simulations, the speed of simulation becomes a very important problem. This thesis therefore presents a new approach to accelerating the speed of simulation.by Chiwon Kim.S.M