Routing.pptx scheduling and production plan
- 1. Routing “Routing means determination of the route to be followed by each part/component being transformed from input/raw material into final product.” Obviously where one single part/product is produced by fixed set of machines the job of routing becomes automatic or mechanized. In continuous production systems with line type or product type layout, no managerial effort is required for routing though different sets of machines may be utilized in manufacturing the products in such systems. For different types of products to be manufactured like in intermittent production system, routing becomes a complex task. Routing of a production order contains complete information of the product to be manufactured, complete details of each operation to be performed, the set up time and the standard time needed for completing the job/product.
- 2. Functions of Routing In all engineering industries, the steps in the direction of preparation for production of a product are more or less the same and occur as follows: (1) The future product exists only as an idea in the mind of the inventor and he draws the sketch. (2)The possible product is deeply analysed, studied and developed to prepare the drawings. (3)The next step is preparation of working drawings which may include the parts and assemblies drawings. (4)Blue prints of the drawings with necessary technical details are prepared.
- 3. When the product is standardized and the work is repetitive, the drawings of the components/parts are prepared with following considerations: (1)The operations and processes required to manufacture the components. (2) The material required for manufacturing of the product. (3) The method of manufacturing. In such cases the completed design prepared by the engineering division and received in production control department will include the following: 1. Blue print of each components 2. List of parts, assemblies and sub assemblies. 3.Complete specifications of material required for each product. 4. Limits and tolerances on each part. 5.Specifications of machining process by which the part is to be produced, 6. Sequence of operations to be performed. 7.Time allowances (set up and operation time) for each operation/process.
- 4. Routing procedure consists of six decisions as mentioned below: (1)Make and Buy Decision: The product to be manufactured and as parts needed are thoroughly analysed to determine which parts/components are to be made and which are to be purchased in view of the following facts: • Cost comparison for making and buying. • Whether the available manpower can be utilized for the purpose of making within the plant. • Whether the existing machines which are idle can be utilized. • Whether the input materials and machines are available in the plant for manufacture or require procurement. Routing Procedure
- 5. (2) Bill of Material: After proper analysis of the product the quality and quantity of materials required is determined and the bill of materials as shown in Fig. From this proforma the quantity of material required for each part is known and accordingly can be procured. Some firms prepare separate lists for finished components and raw materials. To know-how much material is to be purchased or procured the amount of materials in the stores should be known. Routing Procedure
- 7. Routing Procedure (3) Preparation of Route Sheet: The third step of routing procedure is the determination of operations required together with their sequence to manufacture the product. The routing decision establishes the operations necessary for processing the product and lists them in their sequence on route sheet or operation sheet. The operation or route sheet is shown in FIGURE. From this route sheet process, flowchart can be prepared which helps in visualizing operations that may be simplified, combined or eliminated. Further it may help in changing the sequence of operations.
- 9. (4) Lot Size Determination: In case of mass or continuous production systems, the mathematical relations can be used to find out the lot size to be processed. The idea is to determine the number of units to be produced in one lot. If the product is to be produced to fulfil the consumer requirements, the question to determine the lot size does not arise. Routing Procedure
- 10. Routing Procedure (5) Determination of Scrap Factor: The amount of waste which depends on the scraping factors is estimated. The scrap factor is the anticipated normal scrap encountered during the course of manufacturing. As we know that the all components produced at various work stations do not meet the required standards and those which do not pass inspection are to be neglected as scrap. Moreover the total material taken for processing the product does not go into end product. Thus scrap factor determination is an important part of routing procedure. In determining the scrap factor, it should be known where the scrap is going to occur, whether it occurs progressively during the fabrication/production of parts, end assembly or all of sudden after a certain operation or after completion of assembly. If the scrap occurs at one point in the process, a single scrap factor may take care of the anticipated scrap at the point, but when scrap is progressive, cumulative scrap factor is essential to serve the purpose. It would be better to work out the material requirement back ward starting from the desired level of finished product. The usual practice should be to establish these factors from past experience, to determine the manpower, the essential machines/ equipment and the materials. Thus the scrap factor plays an important role in the determination of manpower requirements and loading of various machines.
- 11. Routing Procedure (6) To Provide Necessary Information and Forms: In order to carry out routing as planned various forms and procedures are required which furnish necessary information for the purpose. Various forms used e.g. production order, job ticket, inspection ticket, move order, tool ticket and equipment ticket are shown in Figs. are also prepared in this process. The type of forms used in each department depends upon the type of manufacture. Manufacturing order shown in Figs. which contains name, no., description, quantity of the part to be produced. Serial no. and other information are invariably used in job manufacturing production. If the manufacturing process is simple many plant forms are combined into one sheet called the master Route Sheet. This is a multipurpose sheet which also considerably reduces the paper work.
- 16. Advantages of Routing (1)Effective utilization of available resources. (2)Reduction in production costs. (3)Quality improvement occurs. (4)Productivity of the system improves and (5)Provides a basis for loading & scheduling.
- 17. Factors affecting routing procedure 01. Type of Manufacturing Process/Technique Employed: It is the case of use of line type of layout where the production process is serialized according to the sequence of operations thus making routing automatic. Automobile industries adopt this type of layout. The set up requires change only when new models are introduced. The same type of routing may be adopted in batch production also. 02. Plant Equipment Characteristics: The same product may be possible to manufacture on two or many machines available in the plant. In such cases the cheapest one should be selected, whether small, heavy and automatic or mechanized machine for routing purpose. In order to simplify the process, the routing division should prepare and place on file a machine data card for each and every machine giving characteristics of machine, special attachments (Jigs, fixtures and special tools) and the job range. Records of other facilities like material handling equipment available in the shop may also be useful.
- 18. Factors affecting routing procedure 03. Availability of Plant and Equipment etc.: Recommended actions have to be taken in order to select that equipment or machines, which will help in production of parts at cheapest rate. But sometimes the services of such machines or processes may not be available due to machine load conditions, breakdowns or absenteeism of workers. In such conditions, the routing division must have alternatives available to keep the materials moving for manufacturing of the product. This alternative may be in the form of detours around the breakdown machines/operations or by changing the sequence of operations. 04. Difficulties in Routing due to Non-Availability of Requisite Skilled Manpower: Manpower required in the plant may be highly skilled, semiskilled, or unskilled. On certain particular machines, where high precision work is done, only services of experienced highly skilled workers can be utilized. Routine work may affect the routing procedure in context to manpower are job incentives, lot size, light, heavy or medium sized work etc.
- 19. Techniques of Routing While converting raw material into required goods different operations are to be performed and the selection of a particular path of operations for each piece is termed as ‘Routing’. This selection of a particular path, i.e. sequence of operations must be the best and cheapest to have the lowest cost of the final product. The various routing techniques are: 1. Route card: This card always accompanies with the job throughout all operations. This indicates the material used during manufacturing and their progress from one operation to another. In addition to this the details of scrap and good work produced are also recorded 2. Work sheet: It contains Specifications to be followed while manufacturing. Instructions regarding routing of every part with identification number of machines and This sheet is made for manufacturing as well as for maintenance.
- 20. 3. Route sheet: It deals with specific production order. Generally made from operation sheets. One sheet is required for each part or component of the order. This includes the following: Number and other identification of order. Symbol and identification of part. Number of pieces to be made. Number of pieces in each lot if put through in lots. Operation data which includes: List of operation on the part. Department in which operations are to be performed. Machine to be used for each operation. Fixed sequence of operation, if any. 4. Move order: Though this is document needed for production control, it is never used for routing system. Move order is prepared for each operation as per operation sheet. On this the quantity passed forward, scrapped and to be rectified are recorded. It is returned to planning office when the operation is completed.
- 21. Routing in Job Order, Batch/Intermittent and Continuous Production In job order production, the machines are arranged according to the process type of layout. In this type of production since every time there is new job, the operations change from job to job according to varying specification. Thus the number of operations and their sequence vary considerably. The route sheet is prepared for implementation of each order and hence requires a greater amount of work experience. The product passes through a larger shop floor involving back tracking. The routing is also subjected to production bottlenecks, waiting and rushing according to the work back logs and the machine loads available for them. Thus in job order production. The routing procedure is most difficult and complex.
- 22. In batch order/Intermittent production also generally the equipment is arranged in process type layout. The operations and their sequence differ from batch to batch. The route sheets would require revision whenever the production of the batch changes. Thus routing is relatively simpler as compared to job order production. Routing in continuous/mass manufacturing does not present any problem due to product type of layout, where the machines are arranged according to the sequence of operations which are to be performed on the components. In view of the standardized products, the number of operations and their sequence can be standardized. The equipment is arranged in sequence with automatic material handling systems. The routing becomes a routine and mechanized function as the production required special attention in case of interruption to production flow due to certain factors like machine breakdown or power cuts and shortages of materials. Thus routing in mass production is simplest.