8d8ac73ee91cfb71ae83f9923980f7c9.ppt

- Количество слайдов: 55

Product and Equipment Analysis Chapter 2

Data required for developing good layouts • Product Analysis • Process Analysis

Input Data and Activities • What data are critical to the facility plan? • Muther categorizes the information as: P – Product (what? ) Q – Quantity (how much? ) R – Routing (where? ) S – Support (with what? ) T – Timing (when? )

Product Analysis • • • Bill of Materials Assembly Charts Engineering Drawing Operation Process Chart Route Sheet

Input Data and Activities • Tompkins, White, et. al. , categorize it as: Product Design – what is to be produced? Process Design – how is it to be produced? Schedule Design – when and how much? Product Facility Process Schedule

Product Design • Based on – Function – Aesthetics – Costs – Materials – Manufacturing Methods Driven by market demand • Key point – The product design MUST be finalized before designing the facility. Otherwise a flexible facility is needed.

Tools Used in Product Design • Product/Part Drawings – 2 -D, 3 -D visualization • Exploded Assembly Diagrams

Part drawing

Tools Used in Process Design A partial list (dependent on product and service): • Process Flowcharts and Process Maps • Make vs. Buy • Parts Lists • Bill of Materials • Route Sheets • Assembly Charts • Operations Process Charts • Precedence Diagrams

Process Flowcharts UPS Active Bins Receiving Reserve Storage Quality Assurance Picking Packing Monogramming Embroidering Back to Vendor Hemming Gift Boxing Shipping Parcel Post Next-Day UPS

Process Maps Customer Waiter Place order Is order complete? Salad Chef Dinner Chef N Y Give soup or salad order to chef Prepare soup or salad order Prepare dinner order Give dinner order to chef Drink Get drinks for customer Eat salad or soup Deliver salad or soup order to customer Eat dinner Deliver dinner to customer Receives check Deliver check to customer Gives payment to waiter Receive payment for meal Cash or Credit? Credit Cash Collect change, leave tip Bring change to customer Run credit card through Fill in tip amount Return credit slip to customer Collect tip Give order to waiter

Make vs. Buy? BUY No Can item be purchased? No MAKE Yes Can we make the item? No BUY Yes Is it cheaper for us to make? No BUY Yes Is the capital available? Yes MAKE

Parts List • A listing of component parts.

Bill of Materials • Many different types of “structured parts lists”

Bill of Materials

Company: ARC Inc. Produce: Air Flow Regulator Oper. No. Operation Description 0104 Shape, drill, cut off 0204 Route Sheet Part: Plunger Housing Prepared by: JSU Part No. 3254 Part No. 6/6/03 Machine Type Auto sc. Machine Tooling Setup (hr. ) Oper. Time (hr. ) . 5 in dia coller, cir. Form tool, . 45” diam center drill 5 0. 0057 Machine Slot Chucker and thread 0. 045” slot saw, turret slot 2. 25 0. 0067 0304 Drill 8 holes Auto dr. unit 0. 078” diam twist drill 1. 25 0. 0038 0404 Debur and Blow out Drill press Deburring tool with 0. 5 pilot 0. 0031 SA 1 Enclose Dennison subassembly hydraulic press None 0. 0100 0. 25 Mtls. Parts Alum 1”x 12’

Routing sheet

Assembly Chart 2200 3254 Analog model of the assembly process. 3253 • Circles denote components 3252 • Links denote SA-1 3251 A-1 operations/subassemblies 3250 • Squares represent inspections operation • Begin with the original product 3255 A-2 4150 and to trace the product 4250 disassembly back to its basic 1050 components. A-3 I-1 Pack A-4

Assembly Charts 1 ４ ２ ３ ５ ９ ６ ７ 1０ ８ 1２ 1１

Symbols for 5 basic mfg activities

Operation process chart for 3. 5 volt halogen otoscope

Found by superimposing the route sheets and the assembly chart, a chart results that gives an overview of the flow within the facility. Operations Process Chart

Volume Variety Charts

Volume Variety Chart

Production Requirements – Yield Loss Pi i P i si Oi Pi – Production input to operation i si – Fraction of Pi lost (scrap) Oi – output of process i

Production Requirements – Series Systems P 1 1 2 P 1 s 1 P 2 s 2 . . . n Pnsn On

Example • 5 processes in series • Need 2000 units out

Production Requirements – Non Series Part B Part A Work backward from end of the line. s 1=1% 1 M 1 s 3=2% s 2=2% 2 3 M 2 s 4=1% 4 M 3 s 5=4% 5 M 4 M 2 100, 000 units

Simple equipment selection model • P desired prod rate • t time (in hours) to process one part • m/c avail time (in hours) • m/c efficiency

Simple equipment selection model • Nol Number of good units at output of stage l • Nil Number of units reqd at input of stage l • Sl Scrap at stage l

Simple example 1. Consider a simple jobshop manufacturing system that makes three major “Class A” products requiring five types of machines. The three products include seven parts shown in Table 2. 1 also shows the time standards in units per hour. 2. Assume we an hour has only 55 minutes of productive time and that 5 minutes are lost due to operator or machine unavailability and machine downtime. 3. Dividing the value 55 by the values in Table 2. 1, we get the as well as time per unit. 4. Determine the quantities of machines of each type required to make the standard time per unit. 5. Assuming 12000 “representative” parts are to be made and that only 440 minutes of productive time is available per shift, we can find that we need 4. 9 units of machine A, 5. 85 units of machine B, and 4. 3 units of machine C. 6. Rounding up these numbers gives us 5, 6, and 5 units of machine types A, B, and C, respectively.

Table 2. 1

Table 2. 2

Calculating Equipment Requirements How many pieces of equipment do we need? Pi Ti Ci Ei Ri Mj xj Production rate for operation i (pcs/period) Time per piece for operation i (time/pc) Time available to run operation i (time/period) Efficiency of machine while running Reliability of machine Number of type j machines required Set of operations run on machine j

Example • Consider Machine 2 • x 2={2, 3} • Do similar calculation for other machines • Other factors to consider – Number of shifts – Setup times – Customer lot sizes (smaller require more setups) – Layout type – Maintenance activities

Operator-Machine Charts • Tool for showing activity of both operator and machine along a time line • Also called “multiple activity chart” Example: 1 minute to load 1 minute to unload 6 minute run cycle 0. 5 minute to inspect and pack 0. 5 minute to travel to another machine

Operator Machine Charts

Parameters for an LP equipment selection model • • • • Oi Operation type i, i=1, 2, . . . , o Mi Production equipment type i, i=1, 2, . . . , m Pi Part type i, i=1, 2, . . . , p MHi Material handling system type i, i=1, 2, . . . , n cij cost of performing operation Oi on production equipment type Mj hij cost of handling part type Pi using material handling system type MHj time required to perform operation Oi on production equipment type Mj sij time required to transport part type Pi using material handling carrier type MHj τj time available on production equipment type Mj σj time available on material handling carrier type MHj NOi number of operations Oi to be performed NPi number of units of part type Pi to be manufactured Cj cost of production equipment type Mj Hj cost of material handling system MHj B total budget available

Decision Variables for LP equipment selection model • xij number of operations Oi to be performed on production equipment type Mj • yij number of units of part type Pi to be transported on material handling system type MHj • NMj number of units of production equipment type Mj selected • NMHj number of units of material handling system type MHj selected

LP equipment selection model • Min • Subject to

LP equipment selection model (cont)

Example An automobile engine cylinder manufacturing company that supplies high precision engines to a multinational car manufacturer plans to manufacture several models of cylinder. For planning purposes, it uses the following pseudo products - a standard engine cylinder, a high-technology model, an engine cylinder for sports cars and a luxury car cylinder. The marketing department has demand forecast figures which have been aggregated for the four pseudo models. It has been determined that 2000, 1500, 1800 and 1000 units of the basic, high-tech, sports and luxury models will be demanded during the next six months.

Example The models require one or more of three operations, referred to as O 1, O 2, and O 3. Three machine types and two material handling systems available for performing the three operations and transporting the models. These are denoted as M 1, M 2, M 3 and MH 1, MH 2, respectively. Each machine and handling system may be assumed to be available for 90 percent of the time. The cost of machines M 1, M 2, and M 3 are $230, 000; $250, 000; $310, 000 The cost of material handling carriers MH 1, MH 2 are $90, 000 and $130, 000 The available budget is $10, 000. The following two matrices show the cij's and hij's - that is, the cost of performing operation Oi on production equipment type Mj and cost of handling part type Pi using material handling system type MHj, respectively.

Data for example

LP Model for example • • • • • • MIN 90000 NMH 1 + 130000 NMH 2 + 230000 NM 1 + 250000 NM 2 + 310000 NM 3 + 6 X 11 + 12 X 12 + 8 X 13 + 4 X 21 + 5 X 22 + 4 X 23 + 12 X 31 + 5 X 32 + 5 X 33 + 10 Y 11 + 5 Y 12 + 12 Y 21 + 6 Y 22 + 18 Y 31 + 9 Y 32 + 6 Y 41 + 3 Y 42 SUBJECT TO C 1) X 11 + X 12 + X 13 >= 200 C 2) X 21 + X 22 + X 23 >= 200 C 3) X 31 + X 32 + X 33 >= 150 C 4) - 300 NM 1 + 1. 67 X 11 + 2. 5 X 21 + 0. 83 X 31 <= 0 C 5) - 300 NM 2 + 0. 833 X 12 + 2 X 22 + 2 X 32 <= 0 C 6) - 300 NM 3 + 1. 25 X 13 + 2. 5 X 23 + 2 X 33 <= 0 C 7) Y 11 + Y 12 >= 2000 C 8) Y 21 + Y 22 >= 1500 C 9) Y 31 + Y 32 >= 1800 C 10) Y 41 + Y 42 >= 1000 C 11) - 300 NMH 1 + 0. 1 Y 11 + 0. 0833 Y 21 + 0. 056 Y 31 + 0. 167 Y 41 <= 0 C 12) - 300 NMH 2 + 0. 2 Y 12 + 0. 167 Y 22 + 0. 11 Y 32 + 0. 33 Y 42 <= 0 C 13) 90000 NMH 1 + 130000 NMH 2 + 230000 NM 1 + 250000 NM 2 + 310000 NM 3 <= 1000000 END GIN 5

LP Model Solution • • • • • • VARIABLE NMH 1 NMH 2 NM 1 NM 2 NM 3 X 11 X 12 X 13 X 21 X 22 X 23 X 31 X 32 X 33 Y 11 Y 12 Y 21 Y 22 Y 31 Y 32 Y 41 Y 42 VALUE 2. 000000 1. 000000 200. 000000 59. 880245 140. 119751. 000000 140. 119751 9. 880246. 000000 2000. 000000 1500. 000000 1800. 000000 1000. 000000 REDUCED COST 9000000 105454. 546875 228562. 875000 248353. 593750 308353. 593750. 000000 2. 571524. 860030. 000000 1. 744012. 000000 11. 363637. 000000 7. 663636. 000000 24. 000002

Parameters for LP equipment selection model • rik number of times operation Oi is to be performed on part type Pk • cijk cost of performing operation Oi using production equipment type Mj on part type Pk • tijk time required to perform operation Oi using production equipment type Mj on part type Pk • xijk number of units of operation Oi performed using production equipment type Mj on part type Pk • Cj purchase cost of production equipment type Mj prorated over the planning period

LP equipment selection model • Min • Subject to

Queuing Model Manufacturing engineers at the Widget Manufacturing Company recently convinced their manger to purchase a more expensive, but flexible machine that can do multiple operations simultaneously. The rate at which parts arrived at the machine that was replaced by the flexible machines follows a Poisson process with a mean of 10 parts per hour. The service rate of the flexible machine is 15 units parts per hour compared with the 11 units per hour service rate of the machine it replaced. (All service times follow an exponential distribution. )

Queuing Model The engineers and manager were convinced that the company would have sufficient capacity to meet higher levels of demand, but just after a two months of purchasing the machines it turned out that the input queue to the flexible machine was excessively long and part flow times at this station were so long, that the flexible machine became a severe bottleneck. The engineers noticed that more parts were routed through this machine, and that the parts arrival rate to the flexible machines had increased from 10 per hour to about 20 per hour, but were puzzled why the part flow time at this station doubled from 30 minutes to one hour and the work-n-process (WIP) inventory increased nearly threefold from 5 o 14 when the arrival rte only increased 40%. Use a queuing model to justify the results observed at Widget Manufacturing Company.

M/M/1 Model Solution

Personnel requirements analysis • n number of types of operations • Oi aggregate number of operation type i required on all the pseudo (or real) products manufactured per day • Ti standard time required for an average operation Oi • H total production time available per day • η assumed production efficiency of the plant

Queuing Model The American Automobile Drivers’ Association (AADA) is the only office serving customers in New York’s greater capital district area. Ahead of the busy summer season, the office manager wants to hire additional staff members to help provide these services to members effectively - summer travel planning, membership renewal, disbursing traveler’s checks, airline, hotel, and cruise booking, and other travel related services. It is anticipated that each customer typically requires 10 minutes of service time and customers arrive at the rate of one customer every three minutes. The arrival process is Poisson and the service times are exponentially distributed. Determine how many staff members are required if the average wages and benefits per staff member are $20 per hour and the “cost” to AADA for every hour that a customer waits to be served is $40.

M/M/m Model Solution

Production space requirement sheet