ME6703-COMPUTER-INTEGRATED MANUFACTURING SEVENTH SEMESTER-MECHANICAL ENGINEERING

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1 ME6703-COMPUTER-INTEGRATED MANUFACTURING SEVENTH SEMESTER-MECHANICAL ENGINEERING UNIT-II (POSSIBLE Q&A) 1. What is Process planning? Process planning consists of preparing a set of instructions that describe how to fabricate a part or build an assembly, which will satisfy engineering design specifications. Process planning is the systematic determination of the methods by which product is to be manufactured, economically and competitively. 2. What are the steps involved in Process planning. Steps involved in Process Planning- i) Preliminary analysis and Product design evaluation; ii) Selection of manufacturing process; iii) Selection of Machine Tool; iv) Selection of Tooling and Process parameters; v) Final operation sequence selection 3. What arc the prerequisites for process planning. The other prerequisites for process planning are -a) Part list; b) Annual demand/ batch size; c) Accuracy and surface finish requirement. 4. List the methods of computer aided process planning. The ultimate goal of a system is to integrate design and production data into a system that generates useable process plans. As already mentioned there are two approaches: i. Variant process planning and ii. Generative process planning 5. What is engineering change control? (Nov/Dec-2009) Engineering changes frequently occur and should be communicated to all the personnel concerned. Because engineering changes can affect other aspects of manufacturing, companies often implement systems, which are driven by engineering changes. These systems perform functions such as: i) Automatic distribution of changed drawings to all areas requiring these. ii) Maintenance of history of changes for contract reasons. Effective engineering change control will eliminate wastages and delays in a manufacturing organization. 6. Describe variant process planning A variant process planning system uses the similarity among components to retrieve the existing process plans. A process plan that can be used by a family of components is called a standard plan. A standard plan is stored permanently with a family number as its key. A family represented by a family matrix, which includes all possible members. The variant process planning system has two operational stages: A preparatory stage and a production stage. 7. Describe generative process planning Generative process planning is a system that synthesizes process information in order to create a process plan for a new component automatically. In a generative planning system, process plans are created from information available in manufacturing database without human intervention. Upon receiving the design model, the system can generate the required operations and operation sequences for the component. Knowledge of manufacturing must be captured and encoded into efficient software. 8. Give the main component of generative CAPP systems. CAPP system contains of two main components. a) Manufacturing data base (part description, machine tool library etc.); b) Decision logic (to represent the process planner); c) Process optimization data (as cross reference)

2 9. What arc the benefits of Computer Aided Process Planning. (Nov/Dec-2010) a) Process rationalization: Computer-automated preparation of operation routings is more likely to be consistent, logical, and optimal than its manual counterpart. b) Increased productivity of process planners: With computer-aided process planning, there is reduced clerical effort, fewer errors arc made and the planners have immediate access to the process planning database. c) Reduced turnaround time: This leads to an overall reduction in manufacturing lead time. d) Improved legibility: The computer-prepared document is neater and easier to read than manually written route sheets. f) Incorporation of other application programs 10. What is meant by CAPP? (May/June-2012) CAPP refers to computer-aided process planning. CAPP is used to overcome the drawbacks of manual process planning. With the use of computers in the process planning, one can reduce the routine clerical work of manufacturing engineers. Also it provides the opportunity to generate rational, consistent and optimal plans. 11. What is CMPP system? (May/June-2013) CMPP- Computer Managed Process Planning It is a generative system capable of automatically making process decisions. a) An extensive interactive capability is provided which permits the use to examine and modify a process plan as it is developed. b) This system can be used to plan the fabrication of cylindrical parts involving processes such as: Turning, grinding, and honing, broaching, milling, electrical discharge machining, and drilling used to produce flats, slots, holes, gear teeth, and other non-cylindrical features on a cylindrical part. 12. List any two benefits of CAPP. (Nov/Dec-2011) a) Process rationalization and standardization; b) Increased productivity of process planners; c) Reduced lead time for process planning. 13. What are the basic approaches of CAPP? Retrieval CAPP system, and Generative CAPP system. 14. Differentiate the underlying concepts of variant and generative CAPP systems. (May/June 2012) a)in variant CAPP system, a process plan for a new part is created by recalling, identifying and retrieving an existing plan for a similar part, and making the necessary modifications for the new part. b) Whereas the generative CAPP system automatically generates the process plan based on decision logics and pre-coded algorithms. PART-B 1. Explain Production planning and Production control? Manufacturing planning, process planning, material processing, process engineering and machine routing are a few titles given to the topic referred to here as process planning. Process planning is that function within a manufacturing facility that establishes which machining process and process parameters are to be used to convert a work material (blank) from its initial form (raw material) to a final form defined by an engineering drawing. Process planning is a common task in small batch, discrete parts metal working industries. The process planning activity can be divided into the following steps: Selection of processes and tools Selection of machine tools/manufacturing equipment Sequencing the operations Grouping of operations Selection of work piece holding devices and datum surfaces (set ups)

3 Selection of inspection instruments Determination of production tolerances Determination of the proper cutting conditions Determination of the cutting times and non-machining times (setting time, Inspection time) for each operation Editing the process sheets. All the information determined by the process planning function is recorded on a sheet called process plan. The process plan is frequently called an operation sheet, route sheet or operation planning sheet. This provides the instructions for the production of the part. It contains the operation sequence, processes, process parameters and machine tools. All the information determined by the process planning function is recorded on a sheet called process plan. The process plan is frequently called an operation sheet, route sheet or operation planning sheet. This provides the instructions for the production of the part. It contains the operation sequence, processes, process parameters and machine tools used. Fig 9.1 shows a typical process planning sheet. In conventional production system, a process plan is created by a process planner. It requires a significant amount of time and expertise to determine an optimal routing for each new part design. However, individual engineers will have their own opinions about what constitutes the best routing. Accordingly there are differences among the operation sequences developed by various planners. Efficient process planning requires the service of experienced process planners.

4 Because of the problems encountered with manual process planning, attempts have been made in recent years to capture the logic, judgment and experience required for this important function and incorporates them into computer programmes. Based on the features of a given part, the program automatically generates the sequence of manufacturing operations. The process planning software provides the opportunity to generate production routings which are rational, consistent and perhaps even optimal. It has the following advantages: i. Reduces the skill required of a planner. ii. Reduces the process planning time. iii. Reduces the process planning and manufacturing cost. iv. Creates more consistent plans. v. Produces more accurate plans. vi. Increases productivity 2. Write down the major functions of PPC Some of the important functions of production planning and control are listed below: 1. Materials Function: Raw materials, finished parts and bought out components should be made available in required quantities and at required time to ensure the correct start and end for each operation resulting in uninterrupted production. The function includes the specification of materials (quality & quantity) delivery dates, variety reduction (standardization) procurement and make or buy decisions. 2. Machines and Equipment: This function is related with the detailed analysis of available production facilities, equipment down time, maintenance policy procedure and schedules. Concerned with economy of jigs and fixtures, equipment availability. Thus the duties include the analysis of facilities and making their availability with minimum down time because of breakdowns. 3. Methods: This function is concerned with the analysis of alternatives and selection of the best method with due consideration to constraints imposed. Developing specifications for processes is an important aspect of PPC and determination of sequence of Operations. 4. Process Planning (Routing): It is concerned with selection of path or route which the raw should follow to get transformed in to finished product.the duties include (a) Fixation of path of travel giving due consideration to layout.(b) Breaking don of operations to define each operation in detail.(c) Deciding the set up time and process time for each operation. 5. Estimating: Once the overall method and sequence of operations is fixed and process sheet for each operation is available, then the operations times are estimated. This function is carried out using extensive analysis of operations along with methods and routing and standard times for operation are established using work measurement techniques. 6. Loading and Scheduling: Scheduling is concerned with preparation of machine loads and fixation of Starting and completion dates for each of the operations. Machines have to be loaded according to their capability of

5 performing the given task and according to their capacity. Thus, the duties include:(a) Loading the machines as per their capability and capacity.(b) Determining the start and completion times for each operation.(c) To Co-ordinate with sales department regarding delivery schedules. 7. Dispatching: This is the execution phase of planning. It is the process of setting production activities in motion through release of orders and instructions. It authorizes the start of Production activities by releasing materials, components, tools, fixtures and instruction sheets to the operator. The activities involved are:(a) To assign definite work to definite machines, work centers and men.(b) To issue required materials from stores.(c) To issue jigs, fixtures and make them available at correct point of use.(d) Release necessary work orders, time tickets etc. to authorize timely start of operations.(e) To record start and finish time of each job on each machine or by each man. 8. Expediting: This is the control tool that keeps a close observation on the progress of the work. It is a logical step after dispatching which is called follow-up or Progress. It co-ordinates extensively to execute the production plan. Progressing function can be divided in to three parts, i.e. follow up of materials, follow up of work in process and follow up of assembly.the duties include:1. Identification of bottlenecks and delays and interruptions because of which the production schedule may be disrupted.2. To devise action plans (remedies) for correct the errors.3 To see that production rate is in line with schedule. 9. Inspection: It is a measure control tool. Though the aspects of quality control are the separate function, this is of very much important to PPC both for the execution of the current plans and in scope for future planning. This forms the basis for knowing the limitations with respects to methods, processes etc. which is very much useful for evaluation phase. 10. Evaluation: This stage though neglected is a crucial to the improvement of productive efficiency. A thorough analysis of all the factors influencing the production planning and control helps to identify the weak spots and the corrective action with respect to preplanning and planning will be effected by a feedback. The success of this step depends on the communication, Data and information gathering and analysis 3. Explain CAPP with neat sketch In manufacturing, the goal is to produce components that meet the design specifications. The design specification ensures the functionality aspect. Next step to follow is to assemble these components into final product. Process planning acts as a bridgebetween design and manufacturing by translating design specification into manufacturing process detail. Hence, in general, process planning is a production organization activity that transforms a product design into a set of instruction (sequence, machine tool setup etc.) to manufacture machined part economically and competitively. The information provided in design includes dimensional specification (geometric shape and its feature) and technical specification (tolerance, surface finish etc.) Now-a-days, process planning is applied to many manufacturing industries like metal cutting, sheet metal forming, composite and ceramic fabrication and other manufacturing.

6 Various steps are discussed as follows: The analysis of finished part requirement is the first step in process planning. Initially the features of parts are analyzed. Examples of geometric feature include plane, cylinder, cone step, edge and include fillet. These common features can be modified by the addition of slots, pockets, grooves, holes and others. The second step is the selection of raw work piece shape, size (dimensions and weight), material and other attributes are determined. Weight and material of the raw part are determined by the functional requirement of plan. The next logical step in process planning is to determine the appropriate types of processing operations and their sequences to transform the features, dimensions and tolerances of a part from the raw to the finished state. There may be many ways to produce a design sometimes constraints are also considered like some feature be machined before or after other. Furthermore, the types of machine, available tools as well as batch size influence the process sequence. Next step to be followed in process planning is the selection of machine tools on which these operations are made.some of the factors which influence the selection of machine tool are as follows: (i) Attributes related to work piece, such as desired features, dimensions of work piece, dimensional tolerances and raw material form. (ii) Attributes related to machine tools, e.g. process capability size, mode of operation, tooling capabilities and automatic tool changing capabilities. (iii) Attribute related to production volume, e.g. production quantity and order frequency. Unit cost of production, manufacture lead time and quality are three basic criteria for evaluating the suitability of a machine tool to accomplish an operation. Next step to be followed is the selection of tools work holding devices and inspection equipment s. Features on the work pieces are generated using a combination of machine tool and cutting tools. Work holding devices are used to locate and hold the work piece to generate features. In order to ensure the dimensional accuracy, tolerance and surface finish on the feature, inspection equipment s are required. Part features play a vital role in the selection of machine tools, fixture and inspection equipment.

7 Now sixth step which has to be performed is the determination of machining condition and manufacturing time. The controllable variables of machine condition are cutting speed (υ), feed (f) and depth of cut (d). Minimum cost per piece, maximum production rate and manufacture lead time are same for the model to be optimized for high production and less cost. There are basically two approaches to process planning which are as follows : (i) Manual experience-based process planning, and (ii) Computer-aided process planning method. Manual Experience-based Process Planning The steps mentioned in the previous section are essentially same for manual process planning. Following difficulties are associated with manual experienced based process planning method : 1) It is time consuming and over a period of time, plan developed are not consistent. 2)Feasibility of process planning is dependent on many upstream factors (design and availability of machine tools).downstream manufacturing activities such as scheduling and machine tool allocation are also influenced by such process plan. Therefore, in order to generate a proper process plan, the process planner must have sufficient knowledge and experience. Hence, it is very difficult to develop the skill of the successful process planner and also a time consuming issue. Computer-Aided Process Planning Computer-aided process planning (CAPP) helps determine the processing steps required to make a part after CAP has been used to define what is to be made. CAPP programs develop a process plan or route sheet by following either a variant or a generative approach. The variant approach uses a file of standard process plans to retrieve the best plan in the file after reviewing the design. The plan can then be revised manually if it is not totally appropriate. The generative approach to CAPP starts with the product design specifications and can generate a detailed process plan complete with machine settings. CAPP systems use design algorithms, a file of machine characteristics, and decision logic to build the plans. Expert systems are based on decision rules and have been used in some generative CAPP systems.

8 CAPP has recently emerged as the most critical link to integrated CAD/CAM system into interorganizational flow. Main focus is to optimize the system performance in a global context. The essentiality of computer can easily be understood by taking an example, e.g. if we change the design, we must be able to fall back on a module of CAPP to generate cost estimates for these design changes. Similarly for the case of the breakdown of machines on shop floor. In this case, alternative process plan must be in hand so that the most economical solution for the situation can be adopted. CAPP is the application of computer to assist the human process planer in the process planning function. In its lowest form it will reduce the time and effort required to prepare process plans and provide more consistent process plan. In its most advanced state, it will provide the automated interface between CAD and CAM and in the process achieve the complete integration with in CAD/CAM. Advantages Over Manual Experience-based Process Planning The uses of computers in process plan have following advantages over manual experience-based process planning : (i)it can systematically produce accurate and consistent process plans.(ii) It leads to the reduction of cost and lead times of process plan.(iii) Skill requirement of process planer are reduced to develop feasible process plan. (iv) Interfacing of software for cost, manufacturing lead time estimation, and work standards can easily be done.(v) Leads to the increased productivity of process planar.

9 Steps Involved in CAPP Now-a-days, rapid progress is being made in the automation of actual production process and also the product design element. However, the interface between design and production presents the greatest difficulty in accomplishing integration. CAPP has the potential to achieve this integration. In general, a complete CAPP system has following steps: (i) Design input (ii) Material selection (iii) Process selection (iv) Process sequencing (v) Machine and tool selection (vi) Intermediate surface determination (vii) Fixture selection (viii) Machining parameter selection (ix) Cost/time estimation (x) Plan preparation (xi) Mc tape image generation 4. Explain inventory management. In any business or organization, all functions are interlinked and connected to each other and are often overlapping. Some key aspects like supply chain management, logistics and inventory form the backbone of the business delivery function. Therefore these functions are extremely important to marketing managers as well as finance controllers. Inventory management is a very important function that determines the health of the supply chain as well as the impacts the financial health of the balance sheet. Every organization constantly strives to maintain optimum inventory to be able to meet its requirements and avoid over or under inventory that can impact the financial figures. Inventory is always dynamic. Inventory management requires constant and careful evaluation of external and internal factors and control through planning and review. Most of the organizations have a separate department or job function called inventory planners who continuously monitor, control and review inventory and interface with production, procurement and finance departments. Defining Inventory: Inventory is an idle stock of physical goods that contain economic value, and are held in various forms by an organization in its custody awaiting packing, processing, transformation, use or sale in a future point of time. Any organization which is into production, trading, sale and service of a product will necessarily hold stock of various physical resources to aid in future consumption and sale. While inventory is a necessary evil of any such business, it may be noted that the organizations hold inventories for various reasons, which include speculative purposes, functional purposes, physical necessities etc. From the above definition the following points stand out with reference to inventory: All organizations engaged in production or sale of products hold inventory in one form or other. Inventory can be in complete state or incomplete state. Inventory is held to facilitate future consumption, sale or further processing/value addition. All inventoried resources have economic value and can be considered as assets of the organization. Different Types of Inventory Inventory of materials occurs at various stages and departments of an organization. A manufacturing organization holds inventory of raw materials and consumables required for production. It also holds inventory of semi-finished goods at various stages in the plant with various departments. Finished goods inventory is held at plant, FG Stores, distribution centers etc. Further both raw materials and finished goods those that are in transit at various locations also form a part of inventory depending upon who owns the inventory at the particular juncture. Finished goods inventory is held by the organization at various stocking points or with dealers and stockiest until it reaches the market and end customers.

10 Besides Raw materials and finished goods, organizations also hold inventories of spare parts to service the products. Defective products, defective parts and scrap also forms a part of inventory as long as these items are inventoried in the books of the company and have economic value. Types of Inventory by Function INPUT PROCESS OUTPUT Raw Materials Work In Process Finished Goods Consumables required for processing. Eg : Fuel, Stationary, Bolts & Nuts etc. required in manufacturing Maintenance Items/Consumables Semi-Finished Production in various stages, lying with various departments like Production, WIP Stores, QC, Final Assembly, Paint Shop, Packing, Outbound Store etc. Production Waste and Scrap Finished Goods at Distribution Centers throughout Supply Chain Finished Goods in transit Packing Materials Rejections and Defectives Finished Goods with Stockiest and Dealers Local purchased Items required for production Spare Parts Stocks & Bought Out items Defectives, Rejects and Sales Returns Repaired Stock and Parts Sales Promotion & Sample Stocks Inventory management and supply chain management are the backbone of any business operations. With the development of technology and availability of process driven software applications, inventory management has undergone revolutionary changes. In the last decade or so we have seen adaptation of enhanced customer service concept on the part of the manufacturers agreeing to manage and hold inventories at their customers end and thereby affect Just In Time deliveries. Though this concept is the same in essence different industries have named the models differently. Manufacturing companies like computer manufacturing or mobile phone manufacturers call the model by name VMI - Vendor Managed Industry while Automobile industry uses the term JIT - Just In Time where as apparel industry calls such a model by name - ECR - Efficient consumer response. The basic underlying model of inventory management remains the same.let us take the example of DELL, which has manufacturing facilities all over the world. They follow a concept of Build to Order where in the manufacturing or assembly of laptop is done only when the customer places a firm order on the web and confirms payment. Dell buys parts and accessories from various vendors. DELL has taken the initiative to work with third party service providers to set up warehouses adjacent to their plants and manage the inventories on behalf of DELL s suppliers. The

11 3PL - third party service provider receives the consignments and holds inventory of parts on behalf of Dell s suppliers. The 3PL warehouse houses inventories of all of DELL s suppliers, which might number to more than two hundred suppliers. When DELL receives a confirmed order for a Laptop, the system generates a Bill of material, which is downloaded at the 3PL, processed and materials are arranged in the cage as per assembly process and delivered to the manufacturing floor directly. At this point of transfer, the recognition of sale happens from the Vendor to Dell. Until then the supplier himself at his expense holds the inventory. Let us look at the benefits of this model for both Dell as well as Its Suppliers: 1. With VMI model, Dell has reduced itsin bound supply chain and thereby gets to reduce its logistics and inventory management costs considerably. 2. DELL gets to postpone owning inventory until at the time of actual consumption. Thereby with no inventories DELL has no need for working capital to be invested into holding inventories. 3. DELL does not have to set up inventory operations and employ teams for operations as well as management of inventory functions. Supplier Benefits 1. Supplier gets to establish better relationship and collaboration with DELL with long-term business prospect. 2. By agreeing to hold inventories and effect JIT supplies at the door to DELL, supplier will be in a better position to bargain and get more business from DELL. 3. With VMI model, supplier gets an opportunity to engage in better value proposition with his customer DELL. 4. Supplier gets confirmed forecast for the entire year with commitments from DELL for the quantity off take. 5. VMI managed is managed by 3PL and supplier does not have to engage himself in having to set up and manage inventory operations at DELL s premise. 6. 3PL Managed VMI holds inventories of all suppliers thereby charges each supplier on per pallet basis or per sq.ft basis. Supplier thereby gets to pay on transaction basis without having to marry fixed costs of inventory operations. 5.Explain the types of inventory models Inventory control problems in the real world usually involve multiple products. For example, spare parts systems require management of hundreds or thousands of different items. It is often possible, however, for single-product models to capture all essential elements of the problem, so it is not necessary to include the interaction of different items into the formulation explicitly. Furthermore, multiple-product models are often too unwieldy to be of much use when the number of products involved is very large. For this reason single-product models dominate the literature, and are used most frequently in practice. In the following, we therefore restrict attention largely to instances involving a single product. Even when inventory models are restricted to a single product the number of possible models is enormous, due to the various assumptions made about the key variables: demand, costs, and the physical nature of the system. The demand for the product may be deterministic or stochastic; it may completely predictable, or predictable up to some probability distribution only; its probability distribution may even be unknown. Moreover, demand may be stationary or no stationary, and may depend on economic factors that vary randomly over time. The costs involved include ordering/production costs, which are either proportional

12 to the order quantity or are more general. They may incorporate a setup cost, costs for holding the product in stock, and penalty costs for not being able to satisfy demand when it occurs. In addition, a service level approach may be used if it is too difficult to estimate penalty costs. The stream of costs (or expected costs, if there is some uncertainty in demand and/or lead-times) over a finite or infinite horizon is minimized. The average cost criterion compares the order policies with regard to their average cost, while the total cost criterion compares order policies in relation to the present value of their cost-stream. The Basic EOQ Model We start with the classic economic order quantity (EOQ) model, which has formed the basis for a huge number of papers. In this simple model there is one product, which is replenished in continuous units. The demand is known with certainty and occurs at a constant rate λ; shortages are not allowed. The lead-time for each order is zero. The costs are stationary and consist of a fixed cost k, an ordering cost c per unit ordered, and a cost h per time unit that is charged for each unit of on-hand inventory. On the basis of orders of a fixed size q, there is a cycle time (time between two successive arrivals of orders) of length T = q/λ. Since all cycles are identical, the average cost per time unit is then simply the total cost incurred in a single cycle divided by the cycle length, which is identical to There are numerous variants and extensions of the basic EOQ model. Here we can only outline certain lines of research, and refer students to the Bibliography for more detailed information. Permitting backorders enlarges the set of operating policies, and leads to a larger order quantity and a lower total cost compared with the EOQ model. If there is a deterministic lead-time, which is nonzero, then each order should be placed so that it is received exactly when the on-hand stock decreases to zero. The supply process in the EOQ model may result from a production process at constant rate μ > λ. Then C(q) has the same form as in the EOQ model, with h replaced by h(1 λ/μ), and thus becomes smaller while q* becomes larger. In the basic EOQ model the variable cost c is constant for orders of all sizes. However, it is common for suppliers to offer price concessions for large orders. In fact, there are two kinds of discounts: incremental and all-units with cost functions k + c(q), where c(q) = c0q for 0<q<q. 6. Explain manufacturing resource planning ( MRP II) To assist planners in tracking some of the problems associated with inventory control, some kind of feedback loop is needed in the M.R.P. process, not only to automatically re-schedule certain items (when possible), and avoid excessive manual effort in controlling the process, but to detect and report performance that is out of spec (such as a vendor performance report to track on-time delivery performance). This feedback loop is the defining factor for an M.R.P. II system. Though many systems CLAIM to be an M.R.P. II system, few actually fit the mould exactly. Still, with automatic rescheduling capabilities for work orders and/or repetitive build schedules, and reschedule action reports for purchase orders and outside contracting, the amount of actual analysis is reduced

13 significantly. Other information, such as vender performance reports and process utilization reports, also help to measure the performance to plan capability of the manufacturing plant. Even when the production plan is running at optimum performance, companies still often have serious problems with the manufacturing process. Hidden Cost issues associated with manufacturing increase the total cost of manufacturing, but are extremely hard to track. Some of these Hidden Costs can be caused by excess P.O. rescheduling or excessive crash buy programs, excess and/or obsolete inventory, or planning problems that cause incorrectly stocked finished goods (too much of one, not enough of the other) that result in shortages. Another hidden cost issue might be frequent line stops related to a limiting process (such as a wave solder machine or component inserter), as well as material shortages and excessive kitting of common components. In addition, potential revenue losses from excessively long customer order lead times, or poor on-time customer delivery performance, are real problems, but very difficult to track and measure. As such, none of these problems are tracked nor reported by any standard M.R.P. or M.R.P. II system. To help solve these problems, and improve the company s competativeness and profitability, beyond existing capabilities, the M.R.P. system must go beyond the standard definition of M.R.P. II. Manufacturing Resource Planning (MRP II) is defined by APICS (American Production and Inventory Control Society, Estd. 1957) as a method for the effective planning of all resources of a manufacturing company. Ideally, it addresses operational planning in units, financial planning in dollars, and has a simulation capability to answer "what-if" questions and extension of closed-loop MRP. This is not exclusively a software function, but a marriage of people skills, dedication

14 7. Explain the phases SFC Definition Shop floor control comprises the methods and systems used to prioritize, track, and report against production orders and schedules. It includes the procedures used to evaluate current resource status, labor, machine usage, and other information required to support the overall planning, scheduling, and costing systems related to shop floor operation. Shop floor control typically calculates work in process based on a percentage of completion for each order and operation that is useful in inventory valuations and materials planning. Article Shop floor control is responsible for the detailed management of activities and the flow of materials inside the plant, including employees, materials, machines, and production time. Shop floor control activity typically begins after planning (e.g., with MRP, ERP); once planned, orders and purchase requisitions are created. Shop floor control attends to the following functions (sequentially): Planned orders Conversion of planned orders to process/production Production and process order scheduling Capacity requirements planning Material availability assessment Release of production/process orders Material withdrawals Order confirmations Goods receipt documentation Order settlement Shop floor control may also include identifying and assessing vulnerabilities and risks due to the shop floor environment, employees, process, and the technologies employed at the shop-floor level. Based on the assessment of these factors, shop floor control initiates measures to keep risk at an acceptable minimum level. Best practices for shop floor control include: Efficiently execute, prioritize, and release work orders to the shop floor with real-time status of progress and completion. Deliver accurate and up-to-date information on materials consumption and availability, which is essential for reliable inventory planning and costing. Effectively execute change management processes to ensure that the proper revision of products, bills of materials, and processes are always in place for production. Automate shop floor equipment control and data collection to reduce human errors and increase productivity. Provide the correct manufacturing SOPs, technical drawings, and diagnostics to shop floor operators to reinforce training and ensure proper processing. Download setup programs directly to equipment based on product and process specifications. With fully interactive access to shop floor control software, supervisors can monitor shop activities and make better decisions on the spot, especially using mobile computing equipment.

15 In summary, shop floor control within a manufacturing execution system (MES) can improve the productivity of any shop, regardless of its manufacturing style or capacity. Assembling, cutting metal, or fabricating all require common functions; shop floor control programs can adapt to the operation. When evaluating the need for shop floor control, remember that the driving force is data. Properly executed, shop floor control should deliver the right information at the right time to the right place without fail. Consequently, shop floor efficiency and productivity rise appreciably. 8. Discuss ERP with suitable model. Enterprise resource planning (ERP) is an enterprise-wide information system designed to coordinate all the resources, information, and activities needed to complete business processes such as order fulfillment or billing. An ERP system supports most of the business system that maintains in a single database the data needed for a variety of business functions such as Manufacturing, Supply Chain Management, Financials, Projects, Human Resources and Customer Relationship Management. An ERP system is based on a common database and a modular software design. The common database can allow every department of a business to store and retrieve information in real-time. The information should be reliable, accessible, and easily shared. The modular software design should mean a business can select the modules they need, mix and match modules from different vendors, and add new modules of their own to improve business performance. Ideally, the data for the various business functions are integrated. In practice the ERP system may comprise a set of discrete applications, each maintaining a discrete data store within one physical database. The term ERP originally referred to how a large organization planned to use organizational wide resources. In the past, ERP systems were used in larger more industrial types of companies. However, the use of ERP has changed and is extremely comprehensive, today the term can refer to any type of company, no matter what industry it falls in. In fact, ERP systems are used in almost any type of organization large or small. In order for a software system to be considered ERP, it must provide an organization with functionality for two or more systems. While some ERP packages exist that only cover two functions for an organization (QuickBooks: Payroll & Accounting), most ERP systems cover several functions. Today s ERP systems can cover a wide range of functions and integrate them into one unified database. For instance, functions such as Human Resources, Supply Chain Management, Customer Relations Management, Financials, Manufacturing functions and Warehouse Management functions were all once stand alone software applications, usually housed with their own database and network, today, they can all fit under one umbrella the ERP system. An ideal ERP system is when a single database is utilized and contains all data for various software modules. These software modules can include: Manufacturing: Some of the functions include; engineering, capacity, workflow management, quality control, bills of material, manufacturing process, etc. Financials: Accounts payable, accounts receivable, fixed assets, general ledger and cash management, etc. Human Resources: Benefits, training, payroll, time and attendance, etc Supply Chain Management: Inventory, supply chain planning, supplier scheduling, claim processing, order entry, purchasing, etc. Projects: Costing, billing, activity management, time and expense, etc. Customer relationship management (CRM): CRM is a term applied to processes implemented by a company to handle its contact with its customers. CRM software is used to support these processes, storing information on current and prospective customers. Information in the system can be accessed and

16 entered by employees in different departments, such as sales, marketing, customer service, training, professional development, performance management, human resource development, and compensation. Details on any customer contacts can also be stored in the system. The rationale behind this approach is to improve services provided directly to customers and to use the information in the system for targeted marketing. While the term is generally used to refer to a software-based approach to handling customer relationships, most CRM software vendors stress that a successful CRM strategy requires a holistic approach. CRM initiatives often fail because implementation was limited to software installation without providing the appropriate motivations for employees to learn, provide input, and take full advantage of the information systems. Data Warehouse: Usually this is a module that can be accessed by an organizations customers, suppliers and employees. Data warehouse is a repository of an organization s electronically stored data. Data warehouses are designed to facilitate reporting and analysis. This classic definition of the data warehouse focuses on data storage. However, the means to retrieve and analyze data, to extract, transform and load data, and to manage the data dictionary are also considered essential components of a data warehousing system. Many references to data warehousing use this broader context. Thus, an expanded definition for data warehousing includes business intelligence tools, tools to extract, transform, and load data into the repository, and tools to manage and retrieve metadata. In contrast to data warehouses are operational systems which perform day-to-day transaction processing. The process of transforming data into information and making it available to the user in a timely enough manner to make a difference is known as data warehousing. 9. With suitable illustrative example explain master production schedule A master production schedule (MPS) is a plan for individual commodities to be produced in each time period such as production, staffing, inventory, etc. It is usually linked to manufacturing where the plan indicates when and how much of each product will be demanded. [2] This plan quantifies significant processes, parts, and other resources in order to optimize production, to identify bottlenecks, and to anticipate needs and completed goods. Since an MPS drives much factory activity, its accuracy and viability dramatically affect profitability. Typical MPSs are created by software with user tweaking. Due to software limitations, but especially the intense work required by the "master production schedulers", schedules do not include every aspect of production, but only key elements that have proven their control effectively, such as forecast demand, production costs, inventory costs, lead time, working hours, capacity, inventory levels, available storage, and parts supply. The choice of what to model varies among companies and factories. The MPS is a statement of what the company expects to produce and purchase (i.e. quantity to be produced, staffing levels, dates, available to promise, projected balance). The MPS translates the customer demand (sales orders, PIR s), into a build plan using planned orders in a true component scheduling environment. Using MPS helps avoid shortages, costly expediting, last minute scheduling, and inefficient allocation of resources. Working with MPS allows businesses to consolidate planned parts, produce master schedules and forecasts for any level of the Bill of Material (BOM) for any type of part.by using many variables as inputs the MPS will generate a set of outputs used for decision making. Inputs may include forecast demand, production costs, inventory money, customer needs, inventory progress, supply, lot size, production lead time, and capacity. Inputs may be automatically generated by an ERP system that links a sales department with a production department. For instance, when the sales department records a sale, the forecast demand may be automatically shifted to meet the new demand. Inputs may also be inputted manually from forecasts that have also been calculated manually. Outputs may include amounts to be produced, staffing levels, quantity available to promise, and projected available balance. Outputs may be used to create a Material Requirements Planning (MRP) schedule.

17 A master production schedule may be necessary for organizations to synchronize their operations and become more efficient. An effective MPS ultimately will: Give production, planning, purchasing, and management the information to plan and control manufacturing Tie overall business planning and forecasting to detail operations Enable marketing to make legitimate delivery commitments to warehouses and customers Increase the efficiency and accuracy of a company's manufacturing Rough cut capacity planning MPS issues: Width of the time bucket Planning horizon Rolling plan Time fencing Schedule freezing 10. Explain activities of process planning. Process Planning In companies, planning processes can result in increased output, higher precision, and faster turnaround for vital business tasks. A process is described as a set of steps that result in a specific outcome. It converts input into output. Process planning is also called manufacturing planning, material processing, process engineering, and machine routing. It is the act of preparing detailed work instructions to produce a part. It is a complete description of specific stages in the production process. Process planning determines how the product will be produced or service will be provided. Process planning converts design information into the process steps and instructions to powerfully and effectively manufacture products. As the design process is supported by many computer-aided tools, computer-aided process planning (CAPP) has evolved to make simpler and improve process planning and realize more effectual use of manufacturing resources. It has been documented that process planning is required for new product and services. It is the base for designing factory buildings, facility layout and selecting production equipment. It also affects the job design and quality control. Objective of Process Planning: The chief of process planning is to augment and modernize the business methods of a company. Process planning is planned to renovate design specification into manufacturing instructions and to make products within the function and quality specification at the least possible costs. This will result in reduced costs, due to fewer staff required to complete the same process, higher competence, by eradicating process steps such as loops and bottlenecks, greater precision, by including checkpoints and success measures to make sure process steps are completed precisely, better understanding by all employees to fulfil their department objectives. Process planning deals with the selection of the processes and the determination of conditions of the processes. The particular operations and conditions have to be realised in order to change raw material into a specified shape.

18 All the specifications and conditions of operations are included in the process plan. The process plan is a certificate such as engineering drawing. Both the engineering drawing and the process plan present the fundamental document for the manufacturing of products. Process planning influences time to market and productions cost. Consequently the planning activities have immense importance for competitive advantage. Principles of Process Planning General principles for evaluating or enhancing processes are as follows: 1. First define the outputs, and then look toward the inputs needed to achieve those outputs. 2. Describe the goals of the process, and assess them frequently to make sure they are still appropriate. This would include specific measures like quality scores and turnaround times. 3. When mapped, the process should appear as a logical flow, without loops back to earlier steps or departments. 4. Any step executed needs to be included in the documentation. If not, it should be eliminated or documented, depending on whether or not it's necessary to the process.

19 5. People involved in the process should be consulted, as they often have the most current information. Process planning includes the activities and functions to develop a comprehensive plans and instructions to produce a part. The planning starts with engineering drawings, specifications, parts or material lists and a forecast of demand. The results of the planning are routings which specify operations, operation sequences, work centres, standards, tooling and fixtures. This routing becomes a major input to the manufacturing resource planning system to define operations for production activity control purposes and define required resources for capacity requirements planning purposes. Process plans which characteristically offer more detailed, step-by-step work instructions including dimensions linked to individual operations, machining parameters, set-up instructions, and quality assurance checkpoints. Process plans results in fabrication and assembly drawings to support manufacture and annual process planning is based on a manufacturing engineer's experience and knowledge of production facilities, equipment, their capabilities, processes, and tooling. But process planning is very lengthy and the results differ based on the person doing the planning. Major steps in process planning: Process planning has numerous steps to complete the project that include the definition, documentation, review and improvement of steps in business processes used in a company. Definition: The first step is to describe what the process should accomplish. It includes queries like, what is the output of this process? Who receives the output, and how do they define success?, What are the

20 inputs for the process?, Are there defined success measures in place - such as turnaround time or quality scores? And Are there specific checkpoints in the process that need to be addressed? Documentation: During the documentation stage, interviews are conducted with company personnel to determine the steps and actions they take as part of a specific business process. The results of these interviews is written down, generally in the form of a flow chart, with copies of any forms used or attached. These flow charts are given to the involved departments to review, to make sure information has been correctly captured in the chart. Review: Next, the flow charts are reviewed for potential problem areas. Process planning in manufacturing may include the following activities: 1. Selection of raw-stock, 2. Determination of machining methods, 3. Selection of machine tools, 4. Selection of cutting tools, 5. Selection or design of fixtures and jigs, 6. Determination of set-up, 7. Determination of machining sequences, 8. Calculations or determination of cutting conditions, 9. Calculation and planning of tool paths, 10. Processing the process plan Computer Aided Process Planning Manufacturers have been following an evolutionary step to improve and computerize process planning in the following five stages: Stage I - Manual classification; standardized process plans Stage II - Computer maintained process plans Stage III - Variant CAPP Stage IV - Generative CAPP Stage V - Dynamic, generative CAPP Earlier to CAPP, producers attempted to triumph over the issues of manual process planning by basic categorization of parts into families and developing standardized process plans for parts families that is called Stage I. When a new part is initiated, the process plan for that family would be manually recovered, marked-up and retyped. While this improved output but it did not enhance the quality of the planning of processes.

21 Computer-aided process planning originally developed as a device to electronically store a process plan once it was shaped, recover it, amend it for a new part and print the plan. It is called Stage II. Other ability of this stage is table-driven cost and standard estimating systems. Stage III: Computer-aided approach of variant CAPP is based on a Group Technology coding and classification approach to recognize huge number of part attributes or parameters. These attributes permit the system to choose a baseline process plan for the part family and achieve about ninety percent of the planning work. The schemer will add the remaining ten percent of the effort modifying or fine-tuning the process plan. The baseline process plans stored in the computer are manually entered using a super planner concept that is, developing standardized plans based on the accumulated experience and knowledge of multiple planners and manufacturing engineers. Stage IV: It is generative CAPP. In this stage, process planning decision rules are developed into the system. These decision rules will work based on a part's group technology or features technology coding to produce a process plan that will require minimal manual interaction and modification. While CAPP systems move towards being generative, a pure generative system that can create a complete process plan from part classification and other design data is a goal of the future. These types of generative system will utilize artificial intelligence type capabilities to produce process plans as well as be fully integrated in a CIM environment. An additional step in this stage is dynamic, generative CAPP which would consider plant and machine capacities, tooling availability, work center and equipment loads, and equipment status in developing process plans. The process plan developed with a CAPP system at Stage V would differ in due course depending on the resources and workload in the factory. Dynamic, generative CAPP also entails the need for online display of the process plan on a work order oriented basis to cover that the appropriate process plan was provided to the floor. There are numerous advantages of this type of process planning. It can decrease the skill required of a planner. It can reduce the process planning time. It can reduce both process planning and manufacturing cost. It can create more consistent plans. It can produce more accurate plans. It can increase productivity. Automated process planning is done for shortening the lead-time, manufacturability feedback, lowering the production cost and consistent process plans. Advantages of Computer-aided Process Planning include reduced demand on the skilled planner, reduced process planning time, reduced process planning and manufacturing cost, created more consistent plans, produced accurate plans, increased productivity, increased high flexibility, attained high efficiency, attained adequate high product quality and possibility of integration with the other automated functions and systems. Manufacturing Process Planning delivers essential process planning potential for all manufacturing industries. Using Manufacturing Process Planning, process planners can powerfully create and authenticate the original process plan using the product structure from product engineering, modify the plan to specific requirements, and link products and resources to the steps of the plan. To summarize, Process Planning is important action in a production enterprise that verifies which processes, materials, and instructions will be used to produce a product. Process planning describes a

22 manufacturing facility, processes and parameters which are to be used to change materials from a primary form to a predetermined final stage. 11. Differentiate Generative and Variant approach?