Industrial Engineering Department Methods Engineering Chapter 3 Operation Analysis

1. Industrial Engineering DepartmentMethods EngineeringChapter 3 Operation Analysis Eng. Suleiman Daifi

2. Chapter 3: Operation Analysis KEY POINTS • Use operation analysis to improve the method by asking what. • Focus on the purpose of operation by asking why. • Focus on design, materials, tolerances, processes, and tools by asking how. • Focus on the operator and work design by asking who. • Focus on the layout of the work by asking where. • Focus on the sequence of manufacture by asking when. • Always try to simplify by eliminating, combining, and rearranging operations.

3. Operation Analysis • Operation analysis is the third methods step, the one in which analysis takes place and the various components of the proposed method crystallize. • It immediately follows obtaining and presenting facts using a variety of flow process charting tools presented in Chapter 2. • The analyst should review each operation and inspec- tion presented graphically on these charts and should ask a number of questions, the most important of which is why

4. Why Questions • : 1. Why is this operation necessary? • 2. Why is this operation performed in this manner? • 3. Why are these tolerances this close? • 4. Why has this material been specified? • 5. Why has this class of operator been assigned to do the work?

5. Other Questions • The question why immediately suggests other questions, including how, who, where, and when. Thus, analysts might ask, • 1. How can the operation be performed better? • 2. Who can best perform the operation? • 3. Where could the operation be performed at a lower cost or improved quality? • 4. When should the operation be performed to yield the least amount of material handling?

6. Relation with Lean Manufacturing • Lean manufacturing originated with the Toyota Motor Corporation as a means of eliminating waste in the aftermath of the 1973 oil embargo and followed the footsteps of the Taylor sytemof scientific management but in much broader approach, targeting not only manufacturing costs, but also sales, administrative, and capital costs. • Highlights of the Toyota Production System (TPS) included seven types of muda or waste (Shingo, 1987): (1) overproduction, (2) waiting for the next step, (3) unnecessary transportation, (4) inappropriate processing, (5) excess inventory, (6) un- necessary motion, and (7) defective products

7. A corollary to the seven mudasis the 5S system to reduce waste and optimize productivity by maintaining an orderly workplace and consistent methods. The 5S pillars are (1) sort (seiri), (2) set in order (seiton), (3) shine (seiso), (4) standard- ize(seiketsu) and (5) sustain(shitsuke). • Sort focuses on removing all unnecessary items from the workplace and leaving only the bare essentials. Set in order arranges needed items so that they are easy to find and use. Once the clutter is re- moved, shine ensures further cleanliness and tidiness. Once the first three pillars have been implemented, standardize serves to maintain the order and consistent approach to housekeeping and the methods. Finally, sustain maintains the full 5S process on a regular basis.

8. Operation Analysis Main Items 1.0 Operation Purpose 2.0 Part Design 3.0 Tolerance and Specifications 4.0 Materials 5.0 Manufacturing Sequence and Processes 6.0 Setup and Tools 7.0 Materials Handling 8.0 Plant Layout 9.0 Work Design

9. 1- Operation Purpose • The most important of the nine points of operation analysis. • The best way to simplify an operation is to devise some way to get the same or better results at no additional cost. • An analyst’s cardinal rule is to try to eliminate or combine an operation before trying to improve it. • 25 percent of the operations being performed can be eliminated if sufficient study is given to the design and process. • In many instances, the task or the process should not be simplified or improved, but eliminated entirely. • Eliminating an activity saves money on the installation of an improved method, and there is no interruption or delay because no improved method is being developed, tested, and installed. • Operators need not be trained on the new method, and resistance to change is minimized when an unnecessary task or activity is eliminated. • With respect to paperwork, before a form is developed for information transfer, analysts should ask, Is the form really needed? Today’s computer-controlled systems should reduce the generation of forms and paperwork.

10. Unnecessary operations frequently result from improper planning when the job is first set up. • Once a standard routine is established, it is difficult to change, even if such a change would eliminate a portion of the work and make the job easier. • Unnecessary operations often develop because of the improper performance of a previous operation. A second operation must be done to “touch up” or make acceptable the work done by the first operation.

11. To eliminate an operation: Analysts should ask and answer the following question: Can an outside supplier perform the operation more economically- Can we omit the operation without affecting the performance or quality or productivity The need to establish the purpose of each operation before endeavoring to improve the operation. Once the necessity of the operation has been determined, the remaining nine steps to operation analysis should help to determine how it can be improved

12. 2- Part Design • Methods engineers are often inclined to feel that once a design has been accepted, their only recourse is to plan its economical manufacture. • While introducing even a slight design change may be difficult, a good methods analyst should still review every design for possible improvements. • Designs can be changed, and if improvement is the result and the activity of the job is significant, then the change should be made. • To improve the design, analysts should keep in mind the following pointers for lower-cost designs on each component and each subassembly: 1. Reduce the number of parts by simplifying the design. 2. Reduce the number of operations and the length of travel in manufacturing by joining the parts better and by making the machining and assembly easier. 3. Utilize a better material. 4. Liberalize tolerances and rely on key operations for accuracy, rather than on series of closely held limits. 5. Design for manufacturability and assembly, and transportation

13. Note that the first two will help in reducing muda in un appropriate processing, unnecessary transportation, and excess inventory.

14. Forms Design / Redesign The following criteria apply to the development of forms: • 1. Maintain simplicity in the form design, keeping the amount of necessary input information at a minimum. • 2. Provide ample space for each bit of information, allowing for different input methods (writing, typewriter, word processor). • 3. Sequence the information input in a logical pattern. • 4. Color-code the form to facilitate distribution and routing. • 5. Confine computer forms to one page.

15. 3- Tolerance and Specifications • While tolerances and specifications are always considered when reviewing the design, this is usually not sufficient; they should be considered independently of the other approaches to operation analysis. • Designers may have a tendency to incorporate specifications that are more rigid than necessary when developing a product. This can be due to a lack of knowledge about cost and the thought that it is necessary to specify closer tolerances and specifications than are actually needed to have the manufacturing departments produce to the actual required tolerance range. • Methods analysts should be well versed in the details of cost and should be fully aware of what unnecessarily close tolerances and/or rejects can do to the selling price. • Relationship between the increased cost of tighter machining tolerances.

16. Developing quality products in a manner that actually reduces costs is a major tenet of the approach to quality instituted by Taguchi (1986). • This approach involves combining engineering and statistical methods to achieve improvements in cost and quality by optimizing product design and manufacturing methods. • Inspection is a verification of quantity, quality, dimensions, and performance. Such inspections can usually be performed by a variety of techniques: spot inspection, lot-by-lot inspection, or 100 percent inspection. • Spot inspection is a periodic check to ensure that established standards are being realized. • Lot-by-lot inspection is a sampling procedure in which a sample is examined to determine the quality of the production run or lot. The size of the sample depends on the allowable percentage of defective unity and the size of the production lot being checked. • A 100 percent inspection involves inspecting every unit of production and rejecting the defective units. However, experience has shown that this type of inspection does not ensure a perfect product. The monotony of screening tends to create fatigue, thus lowering operator attention. The inspector may pass some defective parts, or reject good parts. Because a perfect product is not ensured under 100 percent inspection, acceptable quality may be realized by the considerably more economical methods of lot-by-lot or spot inspection. • By investigating tolerances and specifications and taking action when desirable, the company can reduce the costs of inspection, minimize scrap, diminish repair costs, and keep quality high. Also the company is addressing the muda of defective products.

17. 4. Materials • One of the first questions an engineer considers when designing a new product is, What material shall be used? Since choosing the correct material may be difficult because of the great variety available, it is often more practical to incorporate a better and more economical material into an existing design. • Methods analysts should consider the following possibilities for the direct and indirect materials utilized in a process: 1. Finding a less expensive and lighter material. 2. Finding materials that are easier to process. 3. Using materials more economically. 4. Using salvage materials. 5. Using supplies and tools more economically. 6. Standardizing materials. 7. Finding the best vendor from the standpoint of price and vendor stocking.

18. 1.0 FINDING A LESS EXPENSIVE AND LIGHTER MATERIAL • Industry is continually developing new processes for producing and refining materials. • Monthly publications summarize the approximate cost per pound of steel sheets, bars, and plates, and the cost of cast iron, cast steel, cast aluminum, cast bronze, thermoplastic and thermosetting resins, and other basic materials. These costs can be used as anchor points from which to judge the application of new materials. • A material that was not competitive in price yesterday may be very competitive today. • A good example is beverage cans • Methods analysts should remember that items such as valves, relays, air cylin- ders, transformers, pipe fittings, bearings, couplings, chains, hinges, hardware, and motors can usually be purchased at less cost than they can be manufactured.

19. 2.0 FINDING A MATERIAL THAT IS EASIER TO PROCESS • Some materials are usually more readily processed than others. • Referring to handbook data on the physical properties usually helps analysts discern which material will react most favorably to the processes to which it must be subjected in its conversion from raw material to finished product. • For example, machinabilityvaries inversely with hardness, and hardness usually varies directly with strength. • Today the most versatile material is reinforced composites. Resin transfer molding can produce more complex parts advantageously from the standpoint of quality and production rate than most other metal and plastic forming procedures. Thus, by specifying a plastic made of reinforcing carbon fibers and epoxy, the analyst can substitute a composite for a metal part, at both a quality and a cost advantage. • This step is also addressing the muda of inappropriate processing.

20. 3.0 USISING MATERIAL MORE ECONOMICALLY • The possibility of using material more economically is a fertile field for analysis. • If the ratio of scrap material to that actually going into the product is high, then greater utilization should be examined. • For example, if the material put into a plastic compression mold is pre-weighed, it may be possible to use only the exact amount required to fill the cavity; excessive flash can also be eliminated. • In another example, sheet metal - glass • Many world-class manufacturers are finding it not only desirable, but absolutely necessary, to take weight out of existing designs. • For example, cars - washing machines, video cameras, VCRs, suitcases, and TV sets. • Today, powder coating is a proven technology that is replacing many other methods of metal finishing.

21. 4.0 USING SALVAGE MATERIALS • Materials can often be salvaged, rather than sold as scrap. • By-productsfrom an unworked portion or scrap section can sometimes offer real possibilities for savings. • If it is not possible to develop a by-product, then scrap materials should be separated to obtain top scrap prices. Separate bins should be provided for tool steel, steel, brass, copper, and aluminum. • Many companies save wooden boxes from incoming shipments • Similarly, meatpackers utilize everything from a cow: hides, bones, even blood, all except the “moo.”

22. 5.0 USING SUPPLIES AND TOOLS FULLY • Management should encourage full use of all shop supplies. • One manufacturer of dairy equipment introduced the policy that no new welding rod was to be distributed to workers without the return of old tips under 2 in long. The cost of welding rods was reduced immediately by more than 15 percent. • If it has been company practice to discard broken tools of this nature, the analyst should investigate the potential savings of a tool salvage program. • Analysts can also find a use for the unworn portions of grinding wheels, emery disks, and so forth. • Also, items such as gloves and rags (خرق)should not be discarded simply because they are soiled(متسخة). Storing dirty items and then laundering them is less expensive than replacing them. • Methods analysts can make a real contribution to a company by simply minimizing waste, one of the mudas in the TPS system.

23. 6.0 STANDARDIZING MATERIALS • Methods analysts should always be alert to the possibility of standardizing materials. • They must minimize the sizes, shapes, grades, and so on of each material utilized in the production and assembly processes. • The typical economies resulting from reductions in the sizes and grades of the materials employed include the following: ■ Purchase orders are used for larger amounts, which are almost always less expensive per unit. ■ Inventories are smaller, since less material must be maintained as a reserve. ■ Fewer entries need to be made in storage records. ■ Fewer invoices need to be paid. ■ Fewer spaces are needed to house materials in the storeroom. ■ Sampling inspection reduces the total number of parts inspected. ■ Fewer price quotations and purchase orders are needed. • The standardization of materials, like other methods improvement techniques, is a continuing process. It requires the continual cooperation of the design, production planning, and purchasing departments and fits in nicely with the 5S system.

24. 7.0 FINDING THE BEST VENDOR • For the vast majority of materials, supplies, and parts, numerous suppliers will quote different prices, quality levels, delivery times, and willingness to hold inventories • It is usually the responsibility of the purchasing department to locate the most favorable supplier. However, the best supplier last year may not be the best one now. • The methods analyst should encourage the purchasing department to rebid the highest-cost materials, supplies, and parts to obtain better prices and superior quality and to increase vendor stocking, where the vendors agree to hold inventories for their customers. • It is not unusual for methods analysts to achieve a 10 percent reduction in the cost of materials and a 15 percent reduction in inventories by regularly pursuing this approach through their purchasing departments. • Perhaps the most important reason for continued Japanese success in the manufacturing sector is the keiretsu. This is a form of business and manufacturing organization that links businesses together. It can be thought of as a web of interlocking relationships among manufacturers—often between a large manufacturer and its principal suppliers. Thus, in Japan such companies as Hitachi and Toyota and other international competitors are able to acquire parts for their products from regular suppliers who produce to the quality called for and are continually looking for improvement so as to provide better prices for the firms in their network. Alert purchasing departments are often able to create relationships with suppliers comparable to the so-called production keiretsu.

25. 5.0 MANUFACTURE SEQUENCE AND PROCESS • The methods engineer must understand that the time utilized by the manufacturing process is divided into three steps: inventory control and planning, setup operations, and in-process manufacturing. • To improve the manufacturing process, the analyst should consider • Rearranging the operations; • Mechanizing manual operations; • Utilizing more efficient facilities on mechanical operations; • Operating mechanical facilities more efficiently; • Manufacturing near the net shape • Using robots all which address the muda of inappropriate processing.

26. (1) REARRANGING OPERATIONS • Rearranging operations often results in savings. • Combining operations usually reduces costs. • Before changing any operation, however, the analyst must consider possible detrimental effects on subsequent operations down the line. Reducing the cost of one operation could result in higher costs for other operations.

27. (2) MECHANIZING MANUAL OPERATIONS • Today, any practicing methods analyst should consider using special-purpose and automatic equipment and tooling, especially if production quantities are large. • Notable among industry’s latest offerings are program controlled, numerically controlled (NC), and computer controlled (CNC) machining and other equipment. • These afford substantial savings in labor cost as well as the following advantages: reduced work-in-process inventory, less parts damage due to handling, less scrap, reduced floor space, and reduced production throughput time. • Other automatic equipment includes automatic screw machines; multiple- spindle drilling, boring, and tapping machines; index-table machine tools; automatic casting equipment combining automatic sand-mold making, pouring, shakeout, and grinding; and automatic painting and plating finishing equipment. • The use of power assembly tools, such as power nut- and screwdrivers, electric or air hammers, and mechanical feeders, is often more economical than the use of hand tools. • The application of mechanization applies not only to process operations, but also to paperwork. For example, bar coding applications can be invaluable to the operations analyst. Bar coding can rapidly and accurately enter a variety of data. Computers can then manipulate the data for some desired objective, such as counting and controlling inventory, routing specific items to or through a process, or identifying the state of completion and the operator currently working on each item in a work-in-process.

28. (3) UTILIZING MORE EFFICIENT MECHANICAL FACILITIES • If an operation is done mechanically, there is always the possibility of a more efficient means of mechanization. • At one company, for example, turbine blade roots were machined by using three separate milling operations. Both the cycle time and the costs were high. When external broaching was introduced, all three surfaces could be finished at once, for considerable time and cost savings. • Another company overlooked the possibility of utilizing a press operation. This process is one of the fastest for forming and sizing processes. A stamped bracket had four holes that were drilled after the bracket was formed. By using a die designed to pierce the holes, the work could be performed in a fraction of the drilling time. • One company in the food industry was checking the weight of various product lines with a balance. This equipment required the operator to note the weight visually, record the weight on a form, and subsequently perform several calculations. A methods engineering study resulted in the introduction of a statistical weight control system. Under the improved method, the operator weighs the product on a digital scale programmed to accept the product within a certain weight range. As the product is weighed, the weight information is transferred to a personal computer that compiles the information and prints the desired report.

29. (4) OPERATING MECHANICAL FACILITIES MORE EFFICIENTLY • A good slogan for methods analysts is, “Design for two at a time.” Usually multiple-die operation in presswork is more economical than single-stage operation. • Multiple cavities in diecasting, molding, and similar processes are viable options when there is sufficient volume. • Many machine tools are operated at a fraction of their possible output.

30. (5) MANUFACTURING NEAR THE NET SHAPE • Using a manufacturing process that produces components closer to the final shape can: • Maximize material use • Reduce scrap • Minimize secondary processing such as final machining and finishing • Permit manufacturing with more environmentally friendly materials. For example, forming parts with powder metals (PM) instead of conventional casting or forging often provides the manufacture of near-net shapes for many components, resulting in dramatic economic savings as well as functional advantages.

31. (6) CONSIDERING THE USE OF ROBOTS • For cost and productivity reasons, it is advantageous today to consider the use of robots in many manufacturing areas. • The principal advantage of integrating a modern robot in the assembly process is its inherent flexibility. It can assemble multiple products on a single system and can be reprogrammed to handle various tasks with part variations. • In addition, robotic assembly can provide consistently repeatable quality with predictable product output. • A robot’s typical life is approximately 10 years. If it is well maintained and if it is used for moving small payloads, the life can be extended to up to 15 years. • Also, if a given robot’s size and configuration are appropriate, it can be used in a variety of operations. For example, a robot could be used to load a die-casting facility, load a quenching tank, load and unload a board drop-hammer forging operation, load a plate glass washing operation, and so on. • In addition to productivity advantages, robots also offer safety advantages. They can be used in work centers where there is danger to the worker because of the nature of the process.

32. 6 SETUP AND TOOLS • REDUCE SETUP TIME Just-in-time (JIT) techniques • UTILIZE THE FULL CAPACITY OF THE MACHINE • INTRODUCE MORE EFFICIENT TOOLING

33. 1- REDUCE SETUP TIME Just-in-time (JIT) techniques • Have become popular in recent years, emphasize decreasing the setup times to the minimum by simplifying or eliminating them. • The SMED (single minute exchange of die) System of the Toyota Production System (Shingo, 1981) is a good example of this approach. • A significant portion of setup time can often be eliminated by ensuring that raw materials are within specifications, tools are sharp, and fixtures are available and in good condition. • Several points should be considered in reducing setup time: 1. Work that can be done while the equipment is running should be done at that time. 2. Use the most efficient clamping. 3.Eliminate machine base adjustment. 4. Use templates or block gages to make quick adjustments to machine stops.

34. 2- UTILIZE THE FULL CAPACITY OF THE MACHINE • A careful review of many jobs often reveals possibilities for utilizing a greater share of the machine’s capacity. • Analysts should also consider positioning one part while another is being machined.

35. 3- INTRODUCE MORE EFFICIENT TOOLING • Just as new processing techniques are continually being developed, new and more efficient tooling should be considered. • Coated cutting tools have dramatically improved the critical wear-resistance/breakage-resistance combination. • For example, TiC-coated tools have provided a 50 to 100 percent increase in speed over uncoated carbide where each has the same breakage resistance. Advantages include harder surfaces, thus reducing abrasive wear; excellent adhesion to the substrates; low coefficient of friction with most work piece materials; chemical inertness; and resistance to elevated temperatures. Carbide tools are usually more cost-effective than high-speed steel tools on many jobs.

36. 7- MATERIAL HANDLING • Material handling includes motion, time, place, quantity, and space constraints: 1- Material handling must ensure that parts, raw materials, in-process materials, finished products, and supplies are moved periodically from location to location. 2-Material handling ensures that no production process or customer is hampered by either the early or late arrival of materials, since each operation requires materials and supplies at a particular time 3- Material handling must ensure that materials are delivered to the correct place. 4- Material handling must ensure that materials are delivered at each location without damage and in the proper quantity. 5- Material handling must consider storage space, both temporary and dormant. A study conducted by the Material Handling Institute revealed that between 30 and 85 percent of the cost of bringing a product to market is associated with material handling. The following five points should be considered for reducing the time spent in handling material: • Reduce the time spent in picking up material; • Use mechanized or automated equipment; • Make better use of existing handling facilities; • Handle material with greater care; and • Consider the application of bar coding for inventory and related applications.

37. (1) REDUCE THE TIME SPENT IN PICKING UP MATERIAL • Material handling is often thought of as only transportation, neglecting consideration of positioning at the workstation, which is equally important. • Since it is often overlooked, workstation positioning of material may offer even greater opportunities for savings than does transportation. Reducing the time spent in picking up material minimizes tiring, costly manual handling at the machine or the workplace. It gives the operator a chance to do the job faster with less fatigue and greater safety. • Usually some type of conveyor or mechanical fingers can bring material to the workstation, thus reducing or eliminating the time needed to pick up the material. • Interfaces between different types of handling and storage equipment should be studied to develop more efficient arrangements.

38. 2- USE MECHANICAL EQUIPMENT • Mechanizing the handling of material usually reduces labor costs, reduces materials damage, improves safety, alleviates fatigue, and increases production. • However, care must be exercised in selecting the proper equipment and methods. Equipment standardization is important because it simplifies operator training, allows equipment interchangeability, and requires fewer repair parts. • An automated guided vehicle (AGV) can replace a driver. AGVs are successfully used in a variety of applications, such as mail delivery. Typically, these vehicles are not programmed; rather, they follow a magnetic or optical guide for a planned route. Stops are made at specific locations for a predetermined period, giving an employee adequate time for unloading and loading. By pressing a “hold” button and then pressing a “start” button at the conclusion of the loading/unloading operation, the operator can lengthen the dwell period at each stop. AGVs can be programmed to go to any location over more than one path. They are equipped with sensing and control instrumentation to avoid collisions with other vehicles. • Mechanization is also useful for manual materials handling, such as palletizing: • Some lift tables are spring- loaded, • Others are pneumatic • Some tilt for easier access into bins, while others rotate, facilitating palletizing.

39. 3- MAKE BETTER USE OF EXISTING HANDLING FACILITIES • To ensure the greatest return from material handling equipment, that equipment must be used effectively. • Both the methods and the equipment should be sufficiently flexible that a variety of material handling tasks can be accomplished under variable conditions. • Palletizing material in temporary and permanent storage allows greater quantities to be transported faster than storing material without the use of pallets, saving up to 65 percent in labor costs. • Sometimes, material can be handled in larger or more convenient units by designing special racks. • If any material handling equipment is used only part of the time, consider the possibility of putting it to use a greater share of the time. • By relocating production facilities or adapting material handling equipment to diversified areas of work, companies may achieve greater utilization.

40. 4- HANDLE MATERIAL WITH GREATER CARE • Industrial surveys indicate that approximately 40 percent of plant accidents happen during material handlingoperations. Of these, 25 percent are caused by lifting and shifting material. • By exercising greater care in handling material, and using mechanical mechanisms wherever possible for material handling, employees can reduce fatigue and accidents. • Records prove that the safe factory is also an efficient factory. • Safety guards at points of power transmission, safe operating practices, good lighting, and good housekeeping are essential to making material handling equipment safer. • Better handling also reduces product damaged.

41. 5- CONSIDER BAR CODING FOR INVENTORY AND RELATED APPLICATIONS • The black bars and white spaces represent digits that uniquely identify both the item and the manufacturer. Once this Universal Product Code (UPC) is scanned by a reader at the checkout counter, the decoded data are sent to a computer that records timely information on labor productivity, inventory status, and sales. • The following five reasons justify the use of bar coding for inventory and related applications: 1. Accuracy.(less than 1 error in 3.4 million characters. 2. Performance. A bar code scanner enters data three to four times faster than typical keyboard entry. 3. Acceptance. Most employees enjoy using the scanning wand 4. Low cost. 5. Portability. • Bar coding is useful for receiving, warehousing, job tracking, labor reporting,, shipping, failure reporting, quality assurance, tracking, production control, and scheduling

42. SUMMARY: MATERIAL HANDLING Analysts should always be looking for ways to eliminate inefficient material handling without sacrificing safety. To assist the methods analyst in this endeavor, the Materials Handling Institute (1998) has developed 10 principles of material handling. • Planning principle. All material handling should be the result of a deliberate plan in which the needs, performance objectives, and functional specifications of the proposed methods are completely defined at the outset. • Standardization principle. Material handling methods, equipment, controls, and software should be standardized within the limits of achieving overall performance objectives and without sacrificing needed flexibility, modularity, and throughput. • Work principle. Material handling work should be minimized without sacrificing productivity or the level of service required of the operation. • Ergonomic principle. Human capabilities and limitations must be recognized and respected in the design of material handling tasks and equipment, to ensure safe and effective operations. • Unit load principle. Unit loads shall be appropriately sized and configured in a way that achieves the material flow and inventory objectives at each stage in the supply chain. • Space utilization principle. Effective and efficient use must be made of all available space. • System principle. Material movement and storage activities should be fully integrated to form a coordinated, operational system that spans receiving, inspection, storage, production, assembly, packaging, unitizing, order selection, shipping, transportation, and returns handling. • Automation principle. Material handling operations should be mechanized and/or automated where feasible, to improve operational efficiency, increase responsiveness, improve consistency and predictability, decrease operating costs, and eliminate repetitive or potentially unsafe manual labor. • Environmental principle. Environmental impacts and energy consumption are criteria to be considered when designing or selecting alternative equipment and material handling systems. • Life-cycle-cost principle. A thorough economic analysis should account for the entire life cycle of all material handling equipment and resulting systems. To reiterate, the predominant principle is that the less a material is handled, the better it is handled, which fits in nicely with eliminating the mudas of unnecessary transportation and unnecessary

43. 8 PLANT LAYOUT • The principal objective of effective plant layout is: to develop a production system that permits the manufacture of the desired number of products with the de- sired quality at the least cost. • Physical layout is an important element of an entire production system that embraces operation cards, inventory control, material handling, scheduling, routing, and dispatching. • All these elements must be carefully integrated to fulfill the stated objective. Poor plant layouts result in major costs. • The indirect labor expense of long moves, backtracking, delays, and work stoppages due to bottlenecks in the transportation muda are characteristic of a plant with an antiquated and costly layout.

44. LAYOUT TYPES • Is there one type of layout that tends to be the best? The answer is no. A given layout can be best in one set of conditions and yet poor in a different set of conditions. • In general, all plant layouts represent one or a combination of two basic layouts: = product or straight-line layouts =process or functional layouts The straight-line layout: • the machinery is located such that the flow from one operation to the next is minimized for any product class. • This type of layout is quite popular for certain mass-production manufacture, because material handling costs are lower than for process grouping. Process layout • It is the grouping of similar facilities. Thus, all turret lathes would be grouped in one section, department, or building. Milling machines, drill presses, and punch presses would also be grouped in their respective sections. • This type of arrangement gives a general appearance of neatness and orderliness, and tends to promote good housekeeping. • Also, if production quantities of similar products are limited and there are frequent “job” or special orders, a process layout is more satisfactory.

45. TRAVEL CHARTS • Before designing a new layout or correcting an old one, analysts must accumulate the facts that may influence that layout. • Travel or from-to charts can be helpful in diagnosing problems related to the arrangement of departments and service areas, as well as the location of equipment within a given sector of the plant. • The travel chart: is a matrix that presents the magnitude of material handling that takes place between two facilities per time period. • The unit identifying the amount of handling may be whatever seems most appropriate to the analyst. It can be pounds, tons, handling frequency, and so on. .

46. MUTHER’S SYSTEMATIC LAYOUT PLANNING • A systematic approach to plant layout developed by Muther (1973) is termed systematic layout planning (SLP). • The goal of SLP is to locate two areas with high frequency and logical relationships close to one another using a straightforward six-step procedure:

47. Chart relationships. • In the first step, the relationships between different areas are established and then charted on a special form called the relationship chart (or rel chart for short) • A relationship: is the relative degree of closeness, desired or required, among different activities, areas, departments, rooms, etc., as determined from quantitative flow information (volume, time, cost, routing) from a from-to chart, or more qualitatively from functional interactions or subjective information. • The relationship ratings range in value from 4 to –1, based on the vowels that semantically define the relationship.

48. 2.Space Requirements • In the second step, space requirements are established in terms of square footage. • These values can be calculated based on production requirements, extrapolated from existing areas, projected for future expansion, or fixed by legal standards, such as the ADA or architectural standards. • In addition to square footage, the kind and shape of the area being laid out, or the location with respect to required utilities, may be very important.

49. 3.0 Activity Relation ship Diagram • Activity relationships diagram: a visual representation of the different activities is drawn. • The analyst starts with the absolutely important relationships (A’s), using four short, parallel lines to join the two areas. • The analyst then proceeds to the E’s, using three parallel lines approximately double the length of the A lines. • The analyst continues this procedure for the I’s, O’s, etc., • progressively increasing the length of the lines, while attempting to avoid crossing or tangling the lines. For undesirable relationships, the two areas are placed as far apart as possible, and a squiggly line (representing a spring) is drawn between them. (Some analysts may also define an extremely undesirable relationship with a 2 value and a double squiggly line.)

50. 4. Layout Space Relationships LSR • LSR: a spatial representation is created by scaling the areas in terms of relative size. • Once the analyst is satisfied with the layout, the areas are compressed into a floor plan. • This is typically not as easy as it sounds, and the analyst may want to utilize templates. • In addition, modifications may be made to layout based on material handling requirements (e.g., a shipping or receiving department would necessarily be located on an exterior wall), storage facilities (perhaps similar exterior access requirements), personnel requirements (a cafeteria or restroom located close by), building features (crane activities in a high bay area; forklift operations on the ground floor), and utilities.