Analyzing the Value Stream Mapping to Achieve Lean Manufacturing via Line Balancing

Value stream mapping (VSM) visually depicts the flow of materials and information as a product passes through the manufacturing process; this information enables companies to meet customer demand by getting these materials and information for improvement at the right place and at the right time. This paper reviews the existing literature on VSM, describes the concepts and techniques of line balancing, and demonstrates through empirical study how the concepts and techniques of line balancing can help optimize VSM implementation to enhance business performance

Possibilities of Simulation of a Technical Line which is subject to the Balancing Process

Technical line balancing is a mean of economic efficiency increasing of some industrial activities. Essentially, to balance a technical line means to organize human operator's activity, to establish manufacturing flux, to project the line so to minimize equipments and operators' pause time, having a use of these as good as possible. In this work we'll describe an algorithm of simulation of a technical process, relied on random generation of the main characteristics of working phases, which will be considered in solving balancing problem of a technical line whereon an only model of a product is assembled, operating times are established and line operating rhythm is fixed.technical phase, workstation, operating time, technical line balancing, simulation.

Applying equal piles approach to disassembly line balancing problem.

International audienceDisassembly process decomposes a product into parts or subassemblies. Due to the uncertainties that occur during this process, designing and balancing a disassembly line is a very challenging problem. To deal with the disassembly line balancing problem a new method which relies on the equal piles approach is proposed

Performance evaluation of a decoupling inventory for hybrid push-pull systems

Nowadays, companies that oer product variety while maintaining short lead times and competitive quality and cost, gain a competitive edge over their competitors. Therefore, hybrid push-pull systems allow for efficiently balancing lead times and production costs. Raw materials are `pushed' into the semi-finished good warehouse and customers `pull' products by placing orders. As performance of the decoupling stock is critical to the overall performance of the manufacturing system, we define and analyse a Markovian queueing model with two buers, thereby accounting for both the decoupling stock as well as for possible backlog of orders. In particular, our study assesses the eect of variability in the production process and the ordering process on the performance of the decoupling stock

Decision Support System for Assembly Line Planning

TVGs are entities that carry assembly process descriptions, assembly time estimations, product workspaces and other meta-information. These TVGs get assigned to workstations during line balancing. In order to ensure that line workers do not intrude upon each other’s workspace, product workspaces are needed. Generating and maintaining product workspace information for every TVG is automated by use of the Bauraum Identification Tool developed in this research. All assembly work instructions must have time studies. Methods Time Measurement (MTM) are charts that provide assembly time estimations based on the part information. There are 22 MTM tables and several pieces of information are required to arrive at a time study. Using MTM tables to generate assembly time estimates is an error-prone process. The MTM estimate generator developed provides support by presenting a reduced set of MTM tables. Automated line balancing algorithms have not been able to capture all expert knowledge. The output of these algorithms is unintuitive with regards to allowing manual edits. The Line balancing Visualization and Editing Tool takes in the output of one algorithm and visualizes the information. The tool allows users to edit the assignment made by the algorithm and notifies the user of inconvenient assignments

2.5 D Cavity Balancing

Cavity balancing is the process of altering the flow front within a cavity through thickness and design changes such that the desired fill pattern is achieved. The 2 dimensional (2D) cavity-balancing algorithm, developed by Lam and Seow [1] can only handle 2D geometry. This represents a major drawback as most, if not all of the practical injected parts are not 2D parts. To overcome this difficulty, the present investigation has developed a 2.5 dimensional (2.5D) cavity balancing optimization routine implemented within a 2.5 D finite elements domain. The aim of the automated cavity balancing routine is to reduce product development time and to improve product quality. This will lower the level of prerequisite expert knowledge necessary for successful mold and part design. The automated cavity balancing routine has been developed using the concept of flow paths. The hill-climbing algorithm of Lam and Seow is utilized but modified for the generation of flow paths for 2.5D parts. The algorithm has been implemented in a computer program running as an external loop to the MOLDFLOW software. Case studies are provided to demonstrate the efficiency of this routine.Singapore-MIT Alliance (SMA

Human centred manufacturing: methodology for ergonomic previsional evaluation of manual assembly operations

The challenge of flexibility and productivity for manufacturing operations needs a new concept based on “human-centered manufacturing process”. This concept must consider basically the ergonomics of workplaces and workload balancing. The application of this concept is achievable through the detailed knowledge of the interaction between human and workplace, in particular as far as the mechanical load (or work load) arising from product design and from manufacturing process definition (included tools and equipment). The measurement of workload then is a fundamental for new (and existing) workplaces. In this paper is described the methodology that considers the procedure and instruments for measuring ergonomic parameters and the use of EAWS method to assess the ergonomic risk level of the workplace summarized by a score. EAWS considers postural aspects and dynamics of work activity. Design or modification of the workplace can be defined on base of the results obtained by the methodology application

DECISION SUPPORT SYSTEMS FOR ASSEMBLY LINE PLANNING -MODULAR SUBSYTEMS FOR A LARGE SCALE PRODUCTION MANAGEMENT SYSTEM

In the domain of assembly lines, process sheets are entities that carry assembly process descriptions (work instructions), assembly time estimations, product workspaces and other configuration management and control information. These process sheets get assigned to workstations during the process of assembly line balancing. In this research two tools have been developed to aid in the assembly line planning process. In order to ensure that assembly line workers do not intrude upon each other\u27s workspace, two assembly processes operating on the same product workspace must not be assigned to the same station. Generating and maintaining product workspace information for every process sheet is automated by use of the Product Workspace Identification Tool developed in this research. This tool uses CAD data, custom built analysis software, and web-based databases to define, compute, and store product workspace information. All assembly work instructions must have time studies. These time studies are used primarily in line balancing. Methods Time Measurement (MTM) is a set of charts that provide standard assembly time estimations based on the parts (and their surrounding space) that are being assembled. In the adapted version of MTM that is used for this research, there are twenty-two MTM tables and several pieces of information are required to arrive at an assembly time study. Using the MTM tables to generate assembly time estimates is cumbersome simply because the number of work instructions for a given product can run into the thousands. The MTM estimate generator presented in this thesis provides decision support to the process sheet author by presenting a reduced set of MTM tables and also by performing filtering within the MTM tables. Testing and validation of this tool showed that it has a mapping accuracy of 75%. These two tools are modular subsystems of a large production management system

A Study of the Effects of Manufacturing Complexity on Product Quality in Mixed-Model Automotive Assembly

The objective of this research is to test the hypothesis that manufacturing complexity can reliably predict product quality in mixed-model automotive assembly. Originally, assembly lines were developed for cost efficient mass-production of standardized products. Today, in order to respond to diversified customer needs, companies have to allow for an individualization of their products, leading to the development of the Flexible Manufacturing Systems (FMS). Assembly line balancing problems (ALBP) consist of assigning the total workload for manufacturing a product to stations of an assembly line as typically applied in the automotive industry. Precedence relationships among tasks are required to conduct partly or fully automated Assembly Line Balancing. Efforts associated with manual precedence graph generation at a major automotive manufacturer have highlighted a potential relationship between manufacturing complexity (driven by product design, assembly process, and human factors) and product quality, a potential link that is usually ignored during Assembly Line Balancing and one that has received very little research focus so far. The methodology used in this research will potentially help develop a new set of constraints for an optimization model that can be used to minimize manufacturing complexity and maximize product quality, while satisfying the precedence constraints. This research aims to validate the hypothesis that the contribution of design variables, process variables, and human-factors can be represented by a complexity metric that can be used to predict their contribution on product quality. The research will also identify how classes of defect prevention methods can be incorporated in the predictive model to prevent defects in applications that exhibit high level of complexity. The manufacturing complexity model is applied to mechanical fastening processes which are accountable for the top 28% of defects found in automotive assembly, according to statistical analysis of historical data collected over the course of one year of vehicle production at a major automotive assembly plant. The predictive model is validated using mechanical fastening processes at an independent automotive assembly plant. This complexity-based predictive model will be the first of its kind that will take into account design, process, and human factors to define complexity and validate it using a real-world automotive manufacturing process. The model will have the potential to be utilized by design and process engineers to evaluate the effect of manufacturing complexity on product quality before implementing the process in a real-world assembly environment