Process planning and selection
Process selection
Process selection decisions determine the type of productive to be used and the appropriate span of that process. It affect cost, quality, delivery, and flexibility. For, example the manager of a fast food restaurant may be required to decide whether to produce food strictly to customer order or to inventory. The managers must also decide whether to organize the process flow as a high-volume line flow or a low-volume batch-production process.
Process selection decisions: -
Processes can be classified and selected according to product flow and the type of customer order. The customer order is generally of two types- make-to-stock, make-to-order.
1. Make-to-stock: -
It aims to produce in advance and helps to have ready stock when demands occur. This is applicable for a product which has no specific customer at the time of manufacturing. For example: tooth paste, soap etc.
2. Make-to-order: -
It aims to manufacture products only on orders. For example: crane manufacturing, ship, boiler etc.
Factors influence process selection
1. Market conditions
2. Capital requirement
3. Labour
4. Management skills
5. Raw materials
6. Technology
Project characteristics matrix
Make-to-stock Make-to-order
Line flow Soap, paste, fertilizer Automobile assembly line, dumpers, railway coaches.
Intermittent flow Medicines, furniture Automobile assembly line, hospital, custom jewelry
Project Real estate development, commercial paintings Building, dams, bridge, boilers.
A good process selection requires a careful analysis of each of the above factors through several types of studies. A market research should be done to assess potential demand and other market conditions. Future sales should be projected in terms of a range of possible estimates like ‘pessimistic’ most likely ‘optimistic’.
Types of processes
Five types of process are distinguished. They are project, job shop, batch, assembly line and continuous. Each is more or less suited to different product or market situations and each has unique operating characteristics, problems and challenges.
1. Project: - project deals with one-of-a-kind products that are tailored to the unique requirements of each customer. A construction company, with its many kinds and sizes of projects, is an example. Since the products can not be standard, the conversion process must be flexible in its equipment capabilities, human skills and procedures. The conversion process features problem-solving, team work and coordinated design production of unique products.
2. Job shop: - it is appropriate for manufactures of small batch of different products, each of which is custom designed and hence required its own unique set of processing steps, or routing through the production process. Printing process literatures job shop technology. Each product uses only a small portion of the jobs human resources and general purpose equipment.
3. Batch: - batch technology is a step ahead from job process in terms of product standardization but it is not a standardized as the assembly line process. It include wide variety of products in a wide variety of volumes.
4. Assembly line or intermittent: - it is producing a narrow range of standardized products. Laundry appliances are a representative. Example: like design, specialized equipments, human skills and management system can be developed and dedicated to the limited range of products and volumes.
5. Continuous: - users of continuous flow technologies are exemplified by chemical plants and oil refineries, materials and products are produced in continuous, endless flow, rather than in batches of discrete units. The product is highly standardized, assure all of the manufacturing procedures, the sequence of product build-up, material and equipment. Continuous flow technology affords high volume, around the clock operation with capital intensive and specialized automation.
Process planning
It is a complete determination of the specific technological process steps and their sequence to be followed to produce products at the desired quality, quantity and cost. This task is generally managed process engineering. The process engineer should therefore:
a) Determine the method of manufacturing a product.
b) Establish sequence and the type of operations involved.
c) Select the tools and equipments required.
d) Analyse how the manufacturing of the product will fit into the facilities.
The effect of process planning on manufacturing parts and end products is more when compared to other. Hence, their decision will have direct effect on all departments i.e. on costs, methods of manufacturing, quality and production rates.
Factors influencing process planning
Production information
It includes product design, production volume market environment, quality requirement and major technology selection.
Production system information
It includes resource availability and technology capability.
Importance of process planning
It helps in determining the method of manufacturing a product.
It helps in establishing the sequence and type of operation involved.
Selecting the tools and equipments require.
Fitting manufacturing into facilities.
Steps in process planning
Analyse the part print to get an overall picture of what is wanted.
Make recommendation to or consult with product engineers on product design changes.
List the basic operations required to produce the part to the drawing or specifications.
Determine the most practical and economical manufacturing method and the form of tooling required for the each operation.
Devise the best way to combine the operations and put them in sequence.
Specify the gauging required for the process.
Process selection
Process selection decisions determine the type of productive to be used and the appropriate span of that process. It affect cost, quality, delivery, and flexibility. For, example the manager of a fast food restaurant may be required to decide whether to produce food strictly to customer order or to inventory. The managers must also decide whether to organize the process flow as a high-volume line flow or a low-volume batch-production process.
Process selection decisions: -
Processes can be classified and selected according to product flow and the type of customer order. The customer order is generally of two types- make-to-stock, make-to-order.
1. Make-to-stock: -
It aims to produce in advance and helps to have ready stock when demands occur. This is applicable for a product which has no specific customer at the time of manufacturing. For example: tooth paste, soap etc.
2. Make-to-order: -
It aims to manufacture products only on orders. For example: crane manufacturing, ship, boiler etc.
Factors influence process selection
1. Market conditions
2. Capital requirement
3. Labour
4. Management skills
5. Raw materials
6. Technology
Project characteristics matrix
Make-to-stock Make-to-order
Line flow Soap, paste, fertilizer Automobile assembly line, dumpers, railway coaches.
Intermittent flow Medicines, furniture Automobile assembly line, hospital, custom jewelry
Project Real estate development, commercial paintings Building, dams, bridge, boilers.
A good process selection requires a careful analysis of each of the above factors through several types of studies. A market research should be done to assess potential demand and other market conditions. Future sales should be projected in terms of a range of possible estimates like ‘pessimistic’ most likely ‘optimistic’.
Types of processes
Five types of process are distinguished. They are project, job shop, batch, assembly line and continuous. Each is more or less suited to different product or market situations and each has unique operating characteristics, problems and challenges.
1. Project: - project deals with one-of-a-kind products that are tailored to the unique requirements of each customer. A construction company, with its many kinds and sizes of projects, is an example. Since the products can not be standard, the conversion process must be flexible in its equipment capabilities, human skills and procedures. The conversion process features problem-solving, team work and coordinated design production of unique products.
2. Job shop: - it is appropriate for manufactures of small batch of different products, each of which is custom designed and hence required its own unique set of processing steps, or routing through the production process. Printing process literatures job shop technology. Each product uses only a small portion of the jobs human resources and general purpose equipment.
3. Batch: - batch technology is a step ahead from job process in terms of product standardization but it is not a standardized as the assembly line process. It include wide variety of products in a wide variety of volumes.
4. Assembly line or intermittent: - it is producing a narrow range of standardized products. Laundry appliances are a representative. Example: like design, specialized equipments, human skills and management system can be developed and dedicated to the limited range of products and volumes.
5. Continuous: - users of continuous flow technologies are exemplified by chemical plants and oil refineries, materials and products are produced in continuous, endless flow, rather than in batches of discrete units. The product is highly standardized, assure all of the manufacturing procedures, the sequence of product build-up, material and equipment. Continuous flow technology affords high volume, around the clock operation with capital intensive and specialized automation.
Process planning
It is a complete determination of the specific technological process steps and their sequence to be followed to produce products at the desired quality, quantity and cost. This task is generally managed process engineering. The process engineer should therefore:
a) Determine the method of manufacturing a product.
b) Establish sequence and the type of operations involved.
c) Select the tools and equipments required.
d) Analyse how the manufacturing of the product will fit into the facilities.
The effect of process planning on manufacturing parts and end products is more when compared to other. Hence, their decision will have direct effect on all departments i.e. on costs, methods of manufacturing, quality and production rates.
Factors influencing process planning
Production information
It includes product design, production volume market environment, quality requirement and major technology selection.
Production system information
It includes resource availability and technology capability.
Importance of process planning
It helps in determining the method of manufacturing a product.
It helps in establishing the sequence and type of operation involved.
Selecting the tools and equipments require.
Fitting manufacturing into facilities.
Steps in process planning
Analyse the part print to get an overall picture of what is wanted.
Make recommendation to or consult with product engineers on product design changes.
List the basic operations required to produce the part to the drawing or specifications.
Determine the most practical and economical manufacturing method and the form of tooling required for the each operation.
Devise the best way to combine the operations and put them in sequence.
Specify the gauging required for the process.
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