الجزء السادس من الفصل ال 19 من كتاب ASQ انتظروا الجزء الاول من الفصل ال 20 اليوم 8 م ASQ Auditing Handbook 4th Edition J.P.Russell, editor Chapter 19/6 Kaizen Blitz/Event Kaizen is a Japanese word (kai means change or school, zen means good or wisdom). It has come to mean a continual and incremental improvement (as opposed to reengineering, which is a breakthrough, quantum-leap approach). A kaizen blitz or kaizen event is an intense process often lasting three to five consecutive days. It introduces rapid change into an organization by using the ideas and motivation of the people who do the work. It has also been called zero investment improvement. In a kaizen event, a cross-functional team focuses on a target process, stud¬ies it, collects and analyzes data, discusses improvement alternatives, and implements changes. The emphasis is on making the process better, not necessarily perfect. Subprocesses that impact cycle time are a prime target on which to put the synergy of a kaizen team to work. The typical stages of a kaizen event are: • Week before blitz — Wednesday. Train three or four facilitators in kaizen blitz techniques and tools, as well as enhance their facilitation skill level. — Thursday. Target the process to be addressed. — Friday. Gather initial data on the present targeted process. • Blitz week — Monday. Train the participants in kaizen blitz techniques and tools. — Tuesday. Training (AM), process mapping present state (PM). — Wednesday. Process mapping future state. Eliminating non-value-added steps and other waste. Eliminating bottlenecks. Designing new process flow. — Thursday. Test changes, modify as needed. — Friday. Implement the new work flow, tweak the process, document the changes, and be ready for full-scale production on Monday. Prepare follow-up plan. • Post blitz — Conduct follow-up evaluation of change (at an appropriate interval). — Plan the next blitz. Kanban This method is used in a process to signal an upstream supplier (internal or external) that more material or product is needed downstream. Originally it was just a manual card system, but has evolved to more sophisticated signaling methods for some organizations. It is referred to as a pull system because it serves to pull mate¬rial or product from a supplier rather than relying on a scheduling system to push the material or product forward at predetermined intervals. It is said that the kan¬ban method was inspired by Toyotas Taiichi Ohnos visit to a U.S. supermarket. Just-in-Time Just-in-time (JIT) is a material requirements planning system that provides for the delivery of material or product at the exact time and. place where the material or product will be used. Highly coordinated delivery and production systems are required to match delivery to use times. The aim is to eliminate or reduce on-hand inventory (buffer stock) and deliver material or product that requires no or little incoming inspection. Takt Time *> Takt time is the total work time available (per day or per shift) divided by the demand requirements (per day or per shift) of customers. Takt time establishes the production pace relative to the demand. For example, lets say customer orders (demand) average 240 units per day. The production line runs on one shift (480 minutes) per day; so takt time is two minutes. To meet demand one unit must be completed every two minutes. Figure 19.3 shows an analysis of actual time versus takt time for a process consisting of four operations. Line Balancing Line balancing is the method of proportionately distributing workloads within the value stream to meet takt time. The analysis begins with the current state. A balance chart of work steps, time requirements, and operators for each workstation is developed. It shows improvement opportunities by comparing the time of each operation to takt time and total cycle time. Formulae are used to establish a proposed-state balanced line. Standardized Work Standardized work consists of agreed-to work instructions that utilize the best known methods and sequence for each manufacturing or assembly process. Establishing standardized work supports productivity improvement, high quality, and safety of workers. Single-Piece Flow One-piece flow is a product moving through the process one unit at a time. This approach differs from batch processing that produces batches of the same item at a time, moving the product through the process batch by batch. Advantages of single-piece flow are: • It cuts the elapsed time between the customers order and shipment of the order • It reduces or eliminates wait time delays between processing of batches • It reduces inventory, labor, energy, and space required by batch-and-queue processing • It reduces product damage caused by handling and temporary storing of batches • It enables the detection of quality problems early in the process • It allows for flexibility in meeting customer demands • It enables identification of non-value-added steps, thereby eliminating waste Cellular Operations A work cell is a self-contained unit dedicated to performing all the operations to complete a product or a major portion of a production run. Equipment is configured to accomplish: • Sequential processing • Counterclockwise flow to enable operators to optimize use of their right hands as operators move through the cell (moving the part to each subsequent operation) • Shorter movements by close proximity of machines • Position the last operation close to the first operation for the next part • Adaptability of cell to accommodate customers varying demands The most prevalent layout is a U shape (see Figure 19.4), although L, S, and V shapes have been used. Product demand, product mix, and constraints are all considerations in designing a work cell.
Posted on: Mon, 05 Jan 2015 07:00:00 +0000
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