Operations Management Unit 9: Managing Process Constraints 授課教師： 國立臺灣大學工商管理學系 余峻瑜 教授 本課程指定教材為 Operations Management: Processes and Supply Chains, 10th ed., Lee J. Krajewski, Larry P. Ritzman, and Manoj K Malhotra, Pearson Education, ©2013 本講義僅引用部分內容，請讀者自行準備。 1 【本著作除另有註明外，採取創用 CC 「姓名標示 －非商業性－相同方式分享」台灣 3.0 版授權釋出】創用 CC 「姓名標示 －非商業性－相同方式分享」台灣 3.0 版

Case: Radcliffe Infirmary 2 p.263

Managing Constraints 3 Constraints Three types of constraints  Physical, Market, Managerial Bottleneck p.264, 265

Theory of Constraints (TOC) 4 p.265

TOC and Financial Measures 5 p.265 Table 7.1

Key Principles of the TOC 6 p.266 Table 7.2

Practical Application of the TOC 7 TOC involves the implementation of these five steps p.266, 267

Identification and Management of Bottlenecks 8 p.267 Throughput time Identifying bottlenecks

EXAMPLE 7.1: Identifying the Bottleneck in a Service Process 9 p. 267

Floating Bottlenecks 10 Many front-office processes with high customer contacts and divergences have more complicated operations than the simple line flows in Ex The variability in workload creates floating bottlenecks.  This type of variability increases the complexity of day-to- day scheduling.  In this situation, management prefers lower utilization rates, allowing greater slack to absorb unexpected surges in demand.

EXAMPLE 7.2: Identifying the Bottleneck in a Batch Process 11 p.269

Managing Bottlenecks in Manufacturing Processes 12 Identifying bottlenecks:  Note utilization.  Note setup times.  Variability in workloads may create floating bottlenecks.  Ask experienced workers and supervisors.  Look for piled up materials in front of workstations

Managing Bottlenecks in Manufacturing Processes 13 Relieving bottlenecks:  Short-term Carefully monitor schedules and keep bottleneck resource as busy as is practical. Minimize idle time at the bottleneck. Make sure bottleneck has all the resources it needs to stay busy.  Long-term Investments More employees, more shifts, more working days Process improvement / reengineering

Product Mix Decisions 14 Traditional method:  Contribution margin is the amount each product contributes to profit and overhead.  No fixed costs are considered. Bottleneck method:  Note that the firm’s actual throughput and overall profitability depend on the contribution margin generated at the bottleneck.

EXAMPLE 7.3 Determining the Product Mix 15 p

Drum-Buffer-Rope Systems 16 p.272, 273 Figure 7.3 Capacity constrained resource (CCR)  The bottleneck schedule is the drum  The buffer is the time buffer  The rope represents the tying of material release to the drum beat

版權聲明 17 頁碼作品版權圖示來源 / 作者 3 Pearson Education / Lee J., Larry P. Ritzman, and Manoj K Malhotra, Operations Management: Processes and Supply Chains, 10th ed., P. 264, 265. 本作品以著作權法第 46 、 52 、 65 條合理使用。瀏覽日期： 2013/05/01 。 7 Pearson Education / Lee J., Larry P. Ritzman, and Manoj K Malhotra, Operations Management: Processes and Supply Chains, 10th ed., P 本作品以著作權法第 46 、 52 、 65 條合理使用。瀏覽日期： 2013/05/01 。 8 Pearson Education / Lee J., Larry P. Ritzman, and Manoj K Malhotra, Operations Management: Processes and Supply Chains, 10th ed., P 本作品以著作權法第 46 、 52 、 65 條合理使用。瀏覽日期： 2013/05/01 。 10 臺灣大學 / 余峻瑜 教授 12 臺灣大學 / 余峻瑜 教授 13 臺灣大學 / 余峻瑜 教授

版權聲明 18 頁碼作品版權圖示來源 / 作者 14 臺灣大學 / 余峻瑜 教授 16 Pearson Education / Lee J., Larry P. Ritzman, and Manoj K Malhotra, Operations Management: Processes and Supply Chains, 10th ed., P 本作品以著作權法第 46 、 52 、 65 條合理使用。瀏覽日期： 2013/05/01 。 2-9 Case: Radcliffe Infirmary... EXAMPLE 7.1: Identifying the Bottleneck in a Service Process( 各頁標題 ) Pearson Education / Lee J., Larry P. Ritzman, and Manoj K Malhotra, Operations Management: Processes and Supply Chains, 10th ed., P 本作品以著作權法第 46 、 52 、 65 條合理使用。瀏覽日期： 2013/05/01 。 11 EXAMPLE 7.2: Identifying the Bottleneck in a Batch Process Pearson Education / Lee J., Larry P. Ritzman, and Manoj K Malhotra, Operations Management: Processes and Supply Chains, 10th ed., P 本作品以著作權法第 46 、 52 、 65 條合理使用。瀏覽日期： 2013/05/01 。 15, 16 EXAMPLE 7.3 Determining the Product Mix, Drum-Buffer- Rope Systems( 各 頁標題 ) Pearson Education / Lee J., Larry P. Ritzman, and Manoj K Malhotra, Operations Management: Processes and Supply Chains, 10th ed., P. 270, 272. 本作品以著作權法第 46 、 52 、 65 條合理使用。瀏覽日期： 2013/05/01 。

版權聲明 19 頁碼作品版權圖示來源 / 作者 , 15, 16 Pixabay/ Unknown 本作品屬公共領域之著作。瀏覽日期： 2013/05/01 。