09-10-2012, 05:38 PM
SYSTEMIC STRATEGY FOR OPTIMIZING MANUFACTURING OPERATION
[attachment=35856]
INTRODUCTION
A basic and first level definition of manufacturing excellence is making product to customer specification in the most cost effective manner with efficient use of resources (equipment and people) and delivering to the customer on time. Numerous articles and books have been published on manufacturing excellence, which typically encompasses just-in-time manufacturing, total quality management, total productive maintenance and employee involvement.
Five basic objectives of manufacturing excellence are:
• match throughput demand----- make only what is needed
• reduce inventory
• maintain high quality throughout the operation
• reduce lead times
• reduce operating expenses
Achieving these objectives will maximize efficient operation in a cost effective manner while fulfilling customer’s demands for high quality, short lead times, and flexibility.
Operational judgment is key in achieving these objectives various trade-offs exist in reducing inventory versus reducing lead times versus reducing operating expenses. The goals and approaches selected to accomplish these objectives must be grounded through an integrated production and inventory strategy suited for the business’s product customization and delivery performance expectations on a make-to-stock, make-to-order, or assemble-to-order basis.
Driving continual and rapid improvements in these objectives results in continuing improvements in quality, deliver performance expectations, all of which will contribute to the profitability objectives of the enterprise. And additionally
Improvement may vary considerably with the type of industry and from operation to operation within an industry.
In various types of manufacturing operations, opportunities for process improvement are often missed or given incomplete attention because of a lack of discipline in collecting data, analyzing data, and executing a quantitative systematic plan for improvement. The best strategy for capturing improvement opportunities offered by the manufacturing excellence are
• Identifying and quantifying the opportunities for achieving efficient operations through use of asset utilization (AU) process.
• Focusing on these opportunities
BACKGROUND ON POLYMER SHEET FORMING OPERATION
The process for polymer sheet manufacturing is based largely on technology developed many decades ago. The polymer sheet forming process is a continuous casting operation. A schematic example of a typical continuous casting process is shown in the figure. A viscous polymer stream is cast onto a wheel and conveyed through an oven system to create a sheet of specific thickness and characteristics. This sheet is wound onto large rolls, which are then sent to other operations within the company, and the critical features of the sheet include thickness uniformity, absence of defects, and sheet modulus (rheology).
Teams of operators in the polymer operation are responsible for operating a group of machines and performing basic maintenance. Individual process engineers are involved with day-to-day process improvement activities for specific groups of machines. In addition to the machine teams, process improvement teams also drive improvement activities by machine functions. These cross-functional teams are composed of engineers, working within the polymer operations, who cover machine functions such as casting, coating, and conveyance.
Normally we observe that the same product, produced on different machines, exhibited different performance characteristics, and hence a strong held belief was that manufacturing process is as art and not a science.
This case study focuses on a set of machines in the polymer manufacturing operations, and illustrates the application of AU to identify and quantify improvement opportunities through root cause analysis and the application of a process optimization framework to understand and quantify key process-product relationships as a mechanism for capturing the quality improvement opportunities identified by AU.
IDENTIFYING AND QUANTIFYING IMPROVEMENT OPPORTUNITIES
A process for identifying and quantifying opportunities for improvement is AU. The AU process looks at how we can efficiently match demand requirements with equipment utilization and efficient operation.
The goal is not to drive each piece of equipment to 100%AU as it would result in excess inventory or work in process. The Au process that employed in the polymer sheet manufacturing (dealt as a case study) focuses on specific aspects, such as scheduled maintenance, unscheduled maintenance, material flow through the operation, feed stock issues, throughput inefficiencies, production rates, product quality issues, and waste. There are various other approaches similar to AU and these include the overall equipment effectiveness approach described as a part of TPM.
ASSET UTILIZATION DEFINITIONS
Improvement opportunities are identified by measuring an overall AU number and four key manufacturing productivity parameters: Availability, Run time efficiency, Run speed efficiency, and yield.
Availability determines the percent of time that the equipment is available to run product. Downtime, which is time spent on scheduled and unscheduled maintenance, no operation, and idle time caused by lack of customer orders, are tracked by this metric. The no operation category is time that the equipment is down because of situations beyond its control such as equipment being down in other parts of the operation, material flow problems or incoming material, and supplies that are not available or are of poor quality.
Run speed determines the percentage of time that the equipment ran at maximum speed. Time spent running at actual operating speed is compared with the maximum equipment speed. Run speed efficiency is calculated by determining how the actual amount of material produced compares with what amount of material should have been produced at maximum speed or standard rate.
Yield is the percent of time that quality product is produced on the equipment. To calculate yield, the amount of time spent running waste or running substandard product must be assessed.
GUIDELINES FOR IMPLEMENTING THE AU PROCESS
1. The AU process should be employed to drive toward predictable equipment and operations. Unscheduled maintenance and quality loss events marked by AU denote that equipment and processes are not predictable or reliable. Events or conditions leading to unscheduled maintenance and quality losses should be eliminated.
2. Improvement activities should focus on increasing the AU of any capacity-constrained equipment, or in the case of unconstrained equipment, the slowest producing piece of equipment versus across all equipment with a given function.
3. The goal of the AU process is to increase efficient equipment utilization as a way to reduce costs. AU should not be driven to 100%, as it would increase the inventory costs. It is important that each operation make the product mix required in the most efficient manner and in the minimum amount of time needed to meet the demand or make only what is needed. To achieve all these objectives operations must be predictable and reliable and material flow must be synchronized across the operation.
[attachment=35856]
INTRODUCTION
A basic and first level definition of manufacturing excellence is making product to customer specification in the most cost effective manner with efficient use of resources (equipment and people) and delivering to the customer on time. Numerous articles and books have been published on manufacturing excellence, which typically encompasses just-in-time manufacturing, total quality management, total productive maintenance and employee involvement.
Five basic objectives of manufacturing excellence are:
• match throughput demand----- make only what is needed
• reduce inventory
• maintain high quality throughout the operation
• reduce lead times
• reduce operating expenses
Achieving these objectives will maximize efficient operation in a cost effective manner while fulfilling customer’s demands for high quality, short lead times, and flexibility.
Operational judgment is key in achieving these objectives various trade-offs exist in reducing inventory versus reducing lead times versus reducing operating expenses. The goals and approaches selected to accomplish these objectives must be grounded through an integrated production and inventory strategy suited for the business’s product customization and delivery performance expectations on a make-to-stock, make-to-order, or assemble-to-order basis.
Driving continual and rapid improvements in these objectives results in continuing improvements in quality, deliver performance expectations, all of which will contribute to the profitability objectives of the enterprise. And additionally
Improvement may vary considerably with the type of industry and from operation to operation within an industry.
In various types of manufacturing operations, opportunities for process improvement are often missed or given incomplete attention because of a lack of discipline in collecting data, analyzing data, and executing a quantitative systematic plan for improvement. The best strategy for capturing improvement opportunities offered by the manufacturing excellence are
• Identifying and quantifying the opportunities for achieving efficient operations through use of asset utilization (AU) process.
• Focusing on these opportunities
BACKGROUND ON POLYMER SHEET FORMING OPERATION
The process for polymer sheet manufacturing is based largely on technology developed many decades ago. The polymer sheet forming process is a continuous casting operation. A schematic example of a typical continuous casting process is shown in the figure. A viscous polymer stream is cast onto a wheel and conveyed through an oven system to create a sheet of specific thickness and characteristics. This sheet is wound onto large rolls, which are then sent to other operations within the company, and the critical features of the sheet include thickness uniformity, absence of defects, and sheet modulus (rheology).
Teams of operators in the polymer operation are responsible for operating a group of machines and performing basic maintenance. Individual process engineers are involved with day-to-day process improvement activities for specific groups of machines. In addition to the machine teams, process improvement teams also drive improvement activities by machine functions. These cross-functional teams are composed of engineers, working within the polymer operations, who cover machine functions such as casting, coating, and conveyance.
Normally we observe that the same product, produced on different machines, exhibited different performance characteristics, and hence a strong held belief was that manufacturing process is as art and not a science.
This case study focuses on a set of machines in the polymer manufacturing operations, and illustrates the application of AU to identify and quantify improvement opportunities through root cause analysis and the application of a process optimization framework to understand and quantify key process-product relationships as a mechanism for capturing the quality improvement opportunities identified by AU.
IDENTIFYING AND QUANTIFYING IMPROVEMENT OPPORTUNITIES
A process for identifying and quantifying opportunities for improvement is AU. The AU process looks at how we can efficiently match demand requirements with equipment utilization and efficient operation.
The goal is not to drive each piece of equipment to 100%AU as it would result in excess inventory or work in process. The Au process that employed in the polymer sheet manufacturing (dealt as a case study) focuses on specific aspects, such as scheduled maintenance, unscheduled maintenance, material flow through the operation, feed stock issues, throughput inefficiencies, production rates, product quality issues, and waste. There are various other approaches similar to AU and these include the overall equipment effectiveness approach described as a part of TPM.
ASSET UTILIZATION DEFINITIONS
Improvement opportunities are identified by measuring an overall AU number and four key manufacturing productivity parameters: Availability, Run time efficiency, Run speed efficiency, and yield.
Availability determines the percent of time that the equipment is available to run product. Downtime, which is time spent on scheduled and unscheduled maintenance, no operation, and idle time caused by lack of customer orders, are tracked by this metric. The no operation category is time that the equipment is down because of situations beyond its control such as equipment being down in other parts of the operation, material flow problems or incoming material, and supplies that are not available or are of poor quality.
Run speed determines the percentage of time that the equipment ran at maximum speed. Time spent running at actual operating speed is compared with the maximum equipment speed. Run speed efficiency is calculated by determining how the actual amount of material produced compares with what amount of material should have been produced at maximum speed or standard rate.
Yield is the percent of time that quality product is produced on the equipment. To calculate yield, the amount of time spent running waste or running substandard product must be assessed.
GUIDELINES FOR IMPLEMENTING THE AU PROCESS
1. The AU process should be employed to drive toward predictable equipment and operations. Unscheduled maintenance and quality loss events marked by AU denote that equipment and processes are not predictable or reliable. Events or conditions leading to unscheduled maintenance and quality losses should be eliminated.
2. Improvement activities should focus on increasing the AU of any capacity-constrained equipment, or in the case of unconstrained equipment, the slowest producing piece of equipment versus across all equipment with a given function.
3. The goal of the AU process is to increase efficient equipment utilization as a way to reduce costs. AU should not be driven to 100%, as it would increase the inventory costs. It is important that each operation make the product mix required in the most efficient manner and in the minimum amount of time needed to meet the demand or make only what is needed. To achieve all these objectives operations must be predictable and reliable and material flow must be synchronized across the operation.