# soal dan jawaban heizer

Post on 04-Oct-2015

6.720 views

Category:

## Documents

Embed Size (px)

DESCRIPTION

soal jawab Heizer from Internet

TRANSCRIPT

• SOAL DAN JAWABAN: MANAJEMENOPERASIONAL

Dari buku Manajemen Operasional oleh Render, Barryand Jay Heizer, Principles Of Operations Management,

Prentice Hall, 9th edition.

Chapter 1, Operations and Productivity

Problem 1:

Mance Fraily, the Production Manager at Ralts Mills, can currently expect his operation toproduce 1000 square yards of fabric for each ton of raw cotton. Each ton of raw cottonrequires 5 labor hours to process. He believes that he can buy a better quality raw cotton,which will enable him to produce 1200 square yards per ton of raw cotton with the same laborhours.

What will be the impact on productivity (measured in square yards per labor-hour) if hepurchases the higher quality raw cotton?

Problem 2:

C. A. Ratchet, the local auto mechanic, finds that it usually takes him 2 hours to diagnose andfix a typical problem. What is his daily productivity (assume an 8 hour day)?

Mr. Ratchet believes he can purchase a small computer trouble-shooting device, which willallow him to find and fix a problem in the incredible (at least to his customers!) time of 1hour. He will, however, have to spend an extra hour each morning adjusting the computerizeddiagnostic device. What will be the impact on his productivity if he purchases the device?

Problem 3:

Joanna French is currently working a total of 12 hours per day to produce 240 dolls. Shethinks that by changing the paint used for the facial features and fingernails that she canincrease her rate to 360 dolls per day. Total material cost for each doll is approximately \$3.50;she has to invest \$20 in the necessary supplies (expendables) per day; energy costs areassumed to be only \$4.00 per day; and she thinks she should be making \$10 per hour for her

• time. Viewing this from a total (multifactor) productivity perspective, what is her productivityat present and with the new paint?

Problem 4:

How would total (multifactor) productivity change if using the new paint raised Ms. Frenchsmaterial costs by \$0.50 per doll?

Problem 5:

If she uses the new paint, by what amount could Ms. Frenchs material costs increase withoutreducing total (multifactor) productivity?

Problem 1:

1000 sq ydsCurrent labor productivity = 200 sq yds per hour1 ton*5 hours

=

New labor productivity = 1200 sq yds1 ton * 5 hours

240 sq yds per hour=

Productivity improves 20% = ( 240 - 200 ) / 200 = .2

Problem 2:

Current productivity = 8 hours per day2 hours per problem

problems per day= 4

Productivity with computer = 7 hours per day1 hour per problem

problems per day= 7

7 4 3Productivity improves 75% .754 4- = =

Problem 3:

• Currently Using the new paint

Labor 12 hrs * \$10 = \$120 12 hrs * \$10 = \$ 120

Material 240 * \$3.50 = \$840 360 * \$3.50 = \$1260

Supplies = \$ 20 = \$ 20

Energy = \$ 4 = \$ 4

Total Inputs = \$984 = \$1404

Productivity 240/984 = 0.24 360/1404 = .26

Problem 4:

If the material costs increase by \$0.50 per doll:

Using the new paint

Labor 12 hrs * \$10 = \$ 120

Material 360 * \$4.00 = \$1440

Supplies = \$ 20

Energy = \$ 4

Total Inputs = \$1584

Productivity 360/1584 = 0.23

Problem 5:

From the answer to Problem 3 we know the following:

• Currently Using the new paint

Labor 12 hrs * \$10 = \$120 12 hrs * \$10 = \$ 120

Material 240 * \$3.50 = \$840 360 * \$3.50 = \$1260

Supplies = \$ 20 = \$ 20

Energy = \$ 4 = \$ 4

Total Inputs = \$984 = \$1404

Productivity 240/984 = 0.24 360/1404 = .26

We want to know how high the material cost could go, using the new paint, before theproductivity drops to the current level of 0.24. In mathematical terms we make the materialcost a variable (X), set the new multifactor productivity value to the current level, 0.24, andsolve for X.

360/((\$12x10) + 360 \$(X) + \$20 + \$4) = 0.24

360 = 0.24(\$120 + 360\$(X) + \$20 + \$4)

360 = \$28.8 + 86.4\$(X) + \$4.8 + \$.96

325.44 = 86.4\$(X)

\$(X)= 325.44/86.4 = \$3.7666 @ \$3.77

It follows then that the new paint could raise Materials cost by no more than approximately\$0.27 (the difference between \$3.77 and \$3.50) before Ms. French would experience adecrease in multifactor productivity.

Praktek Masalah: Bab 1, Operasi dan Produktivitas

Masalah 1:Mance Fraily, Manajer Produksi di Ralts Mills, saat ini dapat mengharapkan operasi untukmenghasilkan 1000 meter persegi kain untuk setiap ton kapas mentah. Setiap ton kapasmentah membutuhkan jam kerja 5 untuk diproses. Ia percaya bahwa ia dapat membeli kapasyang lebih baik baku mutu, yang akan memungkinkan dia untuk menghasilkan 1.200 meterpersegi per ton kapas mentah dengan jam kerja yang sama.Apa yang akan menjadi dampak pada produktivitas (diukur dalam meter persegi per tenagakerja-jam) jika ia membeli kapas mentah berkualitas tinggi?

Masalah 2:

• CA Ratchet, mekanik mobil lokal, menemukan bahwa biasanya membawanya 2 jam untukmendiagnosa dan memperbaiki masalah khas. Apa adalah produktivitas sehari-hari(asumsikan satu hari jam 8)?Mr Ratchet percaya bahwa dia dapat membeli perangkat komputer pemecahan masalah kecil,yang akan memungkinkan dia untuk menemukan dan memperbaiki masalah di luar biasa(setidaknya kepada pelanggannya!) Waktu 1 jam. Ia akan, bagaimanapun, harusmenghabiskan satu jam ekstra setiap pagi menyesuaikan perangkat diagnostik komputerisasi.Apa yang akan menjadi dampak pada produktivitas jika ia membeli perangkat?

Masalah 3:Joanna Prancis saat ini sedang bekerja total 12 jam per hari untuk memproduksi 240 boneka.Dia berpikir bahwa dengan mengubah cat digunakan untuk fitur wajah dan kuku bahwa diadapat meningkatkan tingkat ke 360 boneka per hari. biaya bahan Total boneka masing-masingadalah sekitar \$ 3,50; dia harus investasi \$ 20 dalam persediaan yang diperlukan(Expendables) per hari, biaya energi diasumsikan hanya \$ 4,00 per hari, dan ia berpikir iaharus membuat \$ 10 per jam untuk waktunya. Melihat ini dari perspektif (multifaktor)produktivitas total, apa yang produktivitas nya pada saat ini dan dengan cat baru?

Masalah 4:Bagaimana total (multifaktor) perubahan produktivitas olah menggunakan cat baru menaikanbiaya bahan Ms Perancis dengan \$ 0,50 per boneka?

Masalah 5:Jika dia menggunakan cat baru, dengan apa yang bisa jumlah bahan Ms Perancismeningkatkan biaya tanpa mengurangi total (multifaktor) produktivitas?

Chapter 2, Operations Strategy in a GlobalEnvironment

Problem 1:

Identify how changes in the external environment may affect the OM strategy for a company.

For example, what impact are the following factors likely to have on OM strategy?

a. The occurrence of a major storm or hurricane.

b. Terrorist attacks of 9/11/01.

c. The much discussed decrease in the quality of American primary and secondary schoolsystems.

d. Trade Legislation such as WTO and NAFTA and changes in tariffs and quotas.

e. The rapid rate at which the cost of health insurance is increasing.

• f. The Internet.

Problem 2:

Identify how the changes in the internal environment affect the OM strategy for a company.For example, what impact are the following factors likely to have on OM strategy?

a. The increased use of Local and Wide Area Networks (LANs and WANs)

b. An increased emphasis on service

c. The increased role of women in the workplace

d. The seemingly increasing rate at which both internal and external environments change.

Problem 3:

Operations managers are called upon to support the organization's strategy. OM does this withsome combination of one of three strategies. What are these three strategies?

Problem 1:

a. A major storm or hurricane may have considerable impact on a companys facilities andscheduling. Flooding and wind damage can make a facility unusable or significantly reduceits capacity. Stocks of raw materials, especially agricultural products, might be damaged orin short supply. The long-term availability of some materials might be significantlyreduced. There may be a shortage of important services during the recovery. For example,the demand for roofers and builders is high after a major storm and they would like to beable to rapidly increase their capacity to handle the higher demand.

b. Terrorist activity has forced organizations to rethink, and in many cases expand, theirsecurity systems. Firms have also had to reevaluate their supply networks and considerincreasing their inventory safety stock. They may also reassess the risks of foreignlocations and expansion.

c. A decrease in the skill levels of Americans entering the labor market requires thatorganizations place more emphasis on training, turn to automation to obviate the need forhuman labor, and hire from outside the United States.

d. WTO and NAFTA changed the rules for trading, opened new markets, and in someinstances, changed the role of labor versus capital (where labor is especially low cost,emphasis often shifts from the use of capital to the use of labor).

• e. The increasing cost of health insurance adds significantly to the cost of labor. Some largeUS organizations are passing on this increased cost to the employees or reducing otherparts of the benefit package in response to these pressures.

f. The Internet has promoted globalization of markets, and eliminated barriers of geographyand time.

Problem 2:

a. The increased use of LANs and WANs has, among other things, enabled neworganizational structures, the movement of the locus of responsibility further down theorganizational hierarchy (elimination of middle management), and the increasingpracticality of JIT operations

Recommended