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November 17, 2006 |
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Tutorials on Application Software for Job Shop Lean |
Typically, the Lean Thinking Process proposed by James Womack and Daniel Jones is implemented in a factory as follows:
1. Specify Value from the Customer’s Perspective.But, in the case of jobshops, the “Lean Toolkit” for implementing the Womack-Jones process needs to be radically changed and enhanced. Why? Because manual implementation of the Womack-Jones process in any high-variety low-volume environment is going to be slow and cumbersome, inadequate, incomplete and often incorrect! Job Shop Lean relies heavily on effective use of application software and IT (Information Technology) to support the deployment of the Womack-Jones process in high-variety low-volume manufacturing facilities as follows: The primary objective of these software tutorials is to demonstrate that it is not impossible to surmount the challenges posed by the complexity of a high-variety low-volume environment. It just takes a change of attitude, the willingness and ability to learn the relevant tools, and industry projects that provide unquestionable proof that these tools can be successfully used in the real world! |
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TIME |
TOPIC |
| 8:00 – 9:00 a.m. |
• Breakfast |
| 9:00 – 9:45 a.m. | (Shahrukh Irani, Ohio State University) Production Flow Analysis to Achieve Flow in any High-Variety Low-Volume Manufacturing Facility. |
Overview of this Presentation:
Production Flow Analysis (PFA) is a comprehensive method for material flow analysis, part family formation, design of manufacturing cells, and facility layout design that was developed in the early 70’s. In a typical application, PFA would be implemented in four stages – Factory Flow Analysis (FFA), Group Analysis (GA), Line Analysis (LA) and Tooling Analysis (TA). Each stage helps to progressively eliminate delays and cut operational costs in a progressively smaller area of the factory. PFAST (Production Flow Analysis and Simplification Toolkit) is a software tool that has automated the manual methods of Production Flow Analysis. This tutorial will give an overview of PFAST, such as data requirements, input file formats, and categories of outputs in the standard PFAST Analysis Report. A typical session with the software will be demonstrated. Finally, the tutorial will outline how to use the outputs from PFAST to:
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| 9:45 – 10:30 a.m. | (Shahrukh Irani, Ohio State University) Product Mix Segmentation. |
Overview of this Presentation:
In the typical Job Shop Lean deployment project, the first and foremost challenge is to select a representative sample of products out of the 100’s, often 1000’s, of active products being produced, that are the focus for further (detailed) analysis of a large product mix. Given a large product mix (P), how does one choose this sample of products using multiple (often competing or conflicting) criteria, such as Demand or Volume (Q), Routing Similarity (R), Sales or Profit Margin ($) and Demand Stability over Time (T). This tutorial will teach a method – P-Q-R-$-T Analysis – that combines existing methods, such as P-Q Analysis, P-Q-R Analysis, P-R Analysis and P-T Analysis. This tutorial will teach how to use the outputs from PFAST to answer critical questions such as:
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| 10:30 – 10:45 a.m. | • BREAK |
| 10:45 – 11:30 a.m. | (Shahrukh Irani, Ohio State University) Feasibility Analysis for Cellular Manufacturing. |
Overview of this Presentation:
Given a product mix with hundreds, even thousands, of (supposedly) different parts, it becomes a challenge to design some number, X, of independent and stand-alone cells. A primary constraint is the significant sharing of common machines, and overlap of machine requirements, between the different cells. This tutorial will teach how to use the outputs from PFAST for:
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| 11:30 – 12:15 p.m. | (Shahrukh Irani, Ohio State University) Design of a Flexible Manufacturing Cell. |
Overview of this Presentation:
How do we select the shape for the layout of a multi-product multi-machine cell? It is well known that the U-shape of a manufacturing cell facilitates process synchronization, material transfers, WIP control and multi-machine tending by any operator, especially for assembly operations. But, there are 25 other letters in the Roman alphabet! What is the best shape for a cell producing a family of parts with similar but not identical routings? This presentation will describe a computer-aided method to determine, on a case-by-case basis, the best shape for a high-variety low-volume non- assembly cell. The proposed method achieves the following design objectives:
1. Minimize total product travel, 2. Shape curvilinear material flow paths, 3. Create a circulation space within which each operator can attend to multiple machines, 4. Determine logical locations for inventory buffers. |
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| 12:15 - 1:15 p.m. | • LUNCH |
| 1:15 – 2:00 p.m. | (Hosni Adra, CreateASoft, Inc.) Simulation of a Multi-Product Multi-Machine Manufacturing Cell. |
Overview of this Presentation:
The design of a multi-product multi-machine cell extends beyond the initial steps, such as part family formation, machine grouping and cell layout. Problems such as planning floorspace requirements to include WIP, lot sizing, job sequencing at constraint machines, operator-machine assignments, etc. need to be addressed. Simulation software provides a digital mockup of an operational cell that gives the analyst the ability to conduct a variety of what-if scenarios when one or more operational parameters are changed. For example, for any given shift, given the product mix, demand for each product and delivery schedule, the simulation model could help to identify the constraint workcenter. Or, the simulation model could be used to determine the workload imbalance and WIP when the job sequence and kanban lot sizes are simultaneously changed for several products. Or, if the absenteeism of one or more operators necessitates changing the current operator-machine assignments, then new walk routes may need to be determined for each operator based on the actual layout of the cell. This tutorial will illustrate how to model and solve several such problems that arise during a cell design project using SIMCAD PRO. | |
| 2:00 – 2:45 p.m. | (Gregory Quinn, Quinn & Associates, Inc.) Finite Capacity Scheduling of a Multi-Product Multi-Machine Manufacturing Cell. |
Overview of this Presentation:
A multi-product multi-machine cell is essentially a small jobshop! Scheduling methods such as takt time and heijunka and generic kanban simply do not suit this manufacturing system for numerous reasons: Not every order follows the same route, there are due dates to be met, capacity constraints influence setup-dependent sequencing at constraint machines, etc. Therefore, the day-to-day operation of a multi-product multi-machine cell must start with a reliable Gantt Chart that displays a valid schedule for each shift and every day of the week. This is crucial since materials, tools, fixtures, etc. have to be delivered JIT to various machines to ensure on-time start and finish of the scheduled operations. Operators must know when to execute various responsibilities, such as loading/unloading, setup and monitoring of machines, or inspection and packaging of parts. Also, it may be necessary to schedule the deliveries of parts from the cell to external resources in the facility, such as heat treatment or electroplating, that need to process those parts. Or, suppliers may fail to meet their scheduled delivery dates or delivery quantities. Or, customers could call at any time and want their parts expedited or delayed, maybe even cancel their orders. In addition to these challenges, the cell foreman and operators are always under pressure to meet due dates, maximize utilization of capital-intensive assets and minimize operating costs in the cell. This tutorial will demonstrate how the PREACTOR scheduling software makes it possible to operate any complex manual (or automated) non-assembly high-mix medium-to-low volume manufacturing cell on a daily basis. | |
| 2:45 - 3:00 p.m. | • BREAK |
| 3:00 – 3:45 p.m. | (Brian Mayer, Virginia Tech, and Hosni Adra, CreateASoft, Inc.) Comparison of Physical vs. Virtual Shop Clusters for Reorganization of a Ship Repair Facility. |
Overview of this Presentation: This presentation will describe a pilot project to evaluate new organizational structures for a US Navy ship repair facility. These structures are:
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| 3:45 - 4:30 p.m. | ((Shahrukh Irani, Ohio State University) Layout Design of a Multi-Product Multi-Machine Manufacturing Cell. |
Overview of this Presentation: How do we select the shape for the layout of a multi-product multi-machine cell? In the case of assembly operations, it is well known that the U-shape of a manufacturing cell facilitates process synchronization, material transfers, WIP control and multi-machine tending by any operator. But, what is the best shape for a cell producing a family of parts with similar but not identical routings? Well, besides the U, there are 25 other letters in the Roman alphabet! This tutorial will teach a computer-aided method to determine the best shape for a high-variety low-volume non-assembly cell that fulfils the following design objectives:
1. Minimize total product travel, 2. Design material flow paths with only curvilinear shapes, 3. Create a working zone for each operator that allows him/her to quickly circulate among multiple machines, 4. Determine logical locations for inventory buffers. | |
| 4:30 p.m. | Adjourn |
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November 17, 2006 |
