Operations Research: An Introduction 10th Global Edition Hamdy A Taha - Solutions

Explore the ultimate resource for mastering "Operations Research: An Introduction 10th Global Edition" by Hamdy A Taha with our comprehensive solutions. Access the answers key, solution manual, and solutions PDF for all solved problems, ensuring you have the step-by-step answers needed for success. Our test bank and chapter solutions offer detailed questions and answers, ideal for any student or instructor. The textbook's instructor manual complements your learning experience, providing in-depth insights and guidance. Discover the convenience of a free download, and elevate your understanding with our expertly curated content, tailored for your academic journey.

Indicators are measures of constructs.a. Trueb. False
“You cannot manage what you cannot measure” means .a. only tangible goods can be measuredb. it is important to measure with precisionc. measurement provides clarity on the desired resultsd. you have to measure up as a managere. None of the above
PESTEL analysis examines the competitive environment and the threat of substitutes.a. Trueb. False
“Numbers are not always fully numerical” means thata. some arithmetic functions may not apply to a specific data set.b. data collection can be suboptimal.c. correlation does not imply causation.d. you need to use at least two decimal places to be fully numerical.e. some people will not
Which of the following is not part of a business research process?a. Defining the problemb. Collecting necessary datac. Analyzing the environmentd. Taking actione. All of the above are part of a business research process.
A business research framework can be used instead of systems thinking for effective operations management.a. Trueb. False
Which of the following describes suboptimization?a. Optimizing one aspect of an operation to the detriment of the operation as a wholeb. Achieving less-than-optimal results with a decisionc. Being useful in the resolution of subsystem problemsd. Applying a holistic technique for system
Effective systems do not need feedback loops.a. Trueb. False
Why do we use systems thinking in operations management?a. Human bodies are complex biological systems.b. An operation’s performance depends on the performance and interrelationship of its parts.c. It has been used since World War I.d. Engineers find it useful.
Which of the following is not an environmental factor for operational systems?a. Politicsb. Customersc. Corporate cultured. Supplierse. All of the above
A system’s environment is defined by the weather conditions it faces.a. Trueb. False
Which of the following is not typically part of a system?a. Feedback loopsb. Boundariesc. Componentsd. Environmente. All of the above
A resource may be considered inimitable if an underlying path dependency created it.a. Trueb. False
A resource is rare if .a. it is valuableb. competitors do not have itc. it makes the firm competitived. it is protected by patent
A prudent business leader has a financial perspective of strategy that drives operational and marketing decisions.a. Trueb. False
Which of the following is not one of the ways in which operations management contributes to a firm’s competitive advantage?a. By creating a perceived needb. By adding value to a combination of inputsc. By delivering a better serviced. By manufacturing products faster
Waste is considered to be an output.a. Trueb. False
Inputs are strictly tangible.a. Trueb. False
Which of the following is not an elemental transformation function?a. Alterb. Manufacturec. Inspectd. Transport
Operations transform inputs into outputs by .a. handling materialb. creating a competitive advantagec. adding valued. manufacturing
In Example 19.1-1, estimate the area of the circle using the first two columns of the 0-1 random numbers in Table 19.1. (For convenience, go down each column, selecting R1 first and then R2.) How does this estimate compare with the ones given in Figure 19.2?
In the cost model in Section 18.9.1, it is generally difficult to estimate the cost parameter C2 (cost of waiting). As a result, it may be helpful to compute the cost C2 implied by the aspiration levels. Using the aspiration level model to determine c*, we can then estimate the implied C2 by using
A shop uses 10 identical machines. Each machine breaks down once every 7 hrs on the average. It takes half an hour on the average to repair a broken machine. Both the breakdown and repair processes follow the Poisson distribution. Determine the following:(a) The number of repairpersons needed such
The necessary conditions for ETC(c) (defined earlier) to assume a minimum value at c = c* are ETC1c* - 12 Ú ETC1c*2 and ETC1c* + 12 Ú ETC1c*2 Show that these conditions reduce to Ls1c*2 - Ls1c* + 12 …C1 C2… Ls1c* - 12 - Ls1c*2 Apply the result to Example 18.9-2, and show that it yields c* = 4.
A machine shop includes 20 machines and 3 repairpersons. A working machine breaks down randomly according to a Poisson distribution. The repair time per machine is exponential with a mean of 6 minutes. A queuing analysis of the situation shows an average of 57 .8 calls for repair per 8-hr day for
A company leases a wide-area telecommunications service (WATS) telephone line for $2000 a month. The office is open 200 working hours per month. At all other times, the WATS line service is used for other purposes and is not available for company business. Access to the WATS line during business
Tasco Oil owns a pipeline booster unit that operates continuously. The time between breakdowns for each booster is exponential with a mean of 20 hrs. The repair time is exponential with mean 3 hrs. In a particular station, two repairpersons attend 10 boosters. The hourly wage for each repairperson
Solve Example 18.9-2, assuming that C1 = $25 and C2 = $50.
Second Time Around sells popular used items on consignment. Its operation can be viewed as an inventory problem in which the stock is replenished and depleted randomly according to Poisson distributions with rates l and m items per day. Every time unit the item is out of stock, Second Time loses
Suppose in Problem 18-118 that the investor can choose any desired restaurant capacity based on a specific marginal cost for each additional capacity unit requested. Derive the associated general cost model, and define all its components and terms.
Pizza Unlimited sells two franchised restaurant models. Model A has a capacity of 20 groups of customers, and model B can seat 30 groups. The monthly cost of operating model A is $12,000 and that of model B is $16,000. An investor wants to set up a buffetstyle pizza restaurant and estimates that
H&I Industry produces a special machine with different production rates (pieces per hour) to meet customer specifications. A shop owner is considering buying one of these machines and wants to decide on the most economical speed (in pieces per hour) to be ordered. From past experience, the owner
BB&K Groceries is opening a new store boasting “state-of-the-art” check-out scanners. Mr. Bih, one of the owners of B&K, has limited the choices to two scanners:scanner A can process 15 items a minute, and the better-quality scanner B can scan 20 items a minute. The daily (10 hours) cost of
Metalco is in the process of hiring a repairperson for a 10-machine shop. Two candidates are under consideration. The first candidate can carry out repairs at the rate of 5 machines per hour and earns $15 an hour. The second candidate, being more skilled, receives $20 an hour and can repair 8
In Example 18.9-1, do the following:(a) Verify the values of m2, m3, and m4 given in the example.(b) Suppose that the penalty of $48 per job per day is levied only on jobs that are not“in progress” at the end of the day. Which copier yields the lowest total cost per day?
In a service facility with c parallel servers, suppose that customers arrive according to a Poisson distribution, with a mean rate of l. Arriving customers are assigned to servers(busy or free) on a strict rotational basis.(a) Determine the probability distribution of the interarrival time.(b)
Show that the P–K formula reduces to Ls of the 1M/M/12:1GD//2 when the service time is exponential with a mean of 1m time units.
1M/Em/12:1GD//2. Given that the service time is Erlang with parameters m and m(i.e., E5t6 = mm and var5t6 = m m2), show that the P–K formula reduces to Ls = mr +m11 + m2r2 211 - mr2
1M/D/12:1GD//2. Show that for the case where the service time is constant, the P-K formula reduces to P L = p + 2(1 - p) = where and p == AEt).
A product arrives according to a Poisson distribution at the rate of one every 45 minutes.The product requires two tandem operations attended by one worker. The first operation uses a semiautomatic machine that completes its cycle in exactly 28 minutes.The second operation makes adjustments and
Optica makes prescription glasses according to orders received from customers. Each worker is specialized in certain types of glasses. The company has been experiencing unusual delays in the processing of bifocal and trifocal prescriptions. The worker in charge receives 30 orders per 8-hr day. The
Layson Roofing Inc. installs shingle roofs on new and old homes in Arkansas.Prospective customers request the service randomly at the rate of 6 jobs per 30-day month and are placed on a waiting list to be processed on a FCFS basis. Homes sizes vary, but it is fairly reasonable to assume that the
Solve Example 18.7-1, assuming that the service-time distribution is given as follows:*(a) Uniform between 8 and 20 minutes.(b) Normal with m = 10 minutes and s = 3 minutes.(c) Discrete with values equal to 4, 8, and 12 minutes and probabilities .1, .6, and .3, respectively.
In Example 18.7-1, compute the percentage of time the facility is idle.
Verify the following results for the special case of one repairperson 1R = 12: Pn Po K!p" (K-n)!' = (1 + L = K - Po R K!p" (Kn)) (1 - Po) P
Show that the rate of breakdown in the shop can be computed from the formula leff = mR where R is the average number of busy repairpersons.
Verify the expression for pn for the (M/M/R): (GD/K/K) model.
After a long wait, the Newborns were rewarded with quintuplets, two boys and three girls, thanks to the wonders of new medical advances. During the first 5 months, the babies’ life consisted of two states: awake (and mostly crying) and asleep. According to the Newborns, the babies’
Kleen All is a service company that performs a variety of odd jobs, such as yard work, tree pruning, and house painting. The company’s four employees leave the office with the first assignment of the day. After completing an assignment, the employee calls the office requesting instruction for the
An operator attends five automatic machines. After each machine completes a batch run, the operator must reset it before a new batch is started. The time to complete a batch run is exponential with mean 45 minutes. The setup time is also exponential with mean 8 minutes.(a) Determine the average
In the computations in Figure 18.9, it may appear confusing that the average rate of machine breakdown in the shop, leff, increases with the increase in R. Explain why the increase in leff should be expected.
In Example 18.6-8, define and compute the productivity of the repairpersons for R = 1, 2, 3, and 4. Use this information in conjunction with the measure of machine productivity to decide on the number of repairpersons Toolco should hire.
In Example 18.6-8, do the following:(a) Verify the values of leff given in Figure 18.9.*(b) Compute the expected number of idle repairpersons, given R = 4.(c) Compute the probability that all repairpersons are idle, given R = 3.*(d) Compute the probability that the majority (more than half) of
Repeat Problem 18-93 for large r = 9, and show that the same conclusion holds except that the value of c must be higher (at least 14). From the results of Problems 18-93 and 18-94, what general conclusion can be drawn regarding the use of 1M/M/c2:1GD//2 to estimate the results of the
Demonstrate (by using excelPoissonQ.xls or TORA) that for small r = .1, the values of Ls, Lq, Ws, Wq, and pn for c as small as 4 servers, the 1M/M/c2:1GD//2 model can be estimated reliably using the less cumbersome formulas of the 1M/M/2:1GD//2 model for c as small as 4 servers.
New drivers are required to pass written tests before they are given road driving test. These tests are usually administered in the city hall. Records at the City of Springdale show that the average number of written tests is 100 per 8-hr day. The average time needed to complete the test is about
In Example 18.6-7, compute the following:(a) The probability that the investor will sell out completely.(b) The probability that the investor will own at least 20 securities.(c) The probability that the investor will own between 20 and 30 securities, inclusive.(d) The investor’s net annual equity
For 1M/M/c2:1GD/N/2 with which N =c, define ln and mn in terms of the general model (Section 18.5), then show that the expression for pn is given as pn =rn n!p0, n = 1, 2,c, c where p0 = a1 + a cn=1 rn n!b-1
Verify the expression for p0 and Lq for 1M/M/c2:1GD/N/2 when rc= 1.
Prove the following equality for 1M/M/c2:1GD/N/2:leff = mc, where c is the number of busy servers.
Verify the expression for p0 for the 1M/M/c2:1GD/N/2 model, given that rc 1.
At U of A, newly enrolled freshmen students are notorious for wanting to drive their cars to class (even though most of them are required to live on campus and can conveniently make use of the university’s free transit system). During the first couple of weeks of the fall semester, traffic havoc
A small engine repair shop is run by three mechanics. Early in March of each year, people bring in their tillers and lawn mowers for service and maintenance. The shop is willing to accept all the tillers and mowers that customers bring in. However, when new customers see the floor of the shop
Eat & Gas convenience store operates a two-pump gas station. The lane leading to the pumps can house at most 3 cars, excluding those being serviced. Arriving cars go elsewhere if the lane is full. The distribution of arriving cars is Poisson with mean 20 per hour. The time to fill up and pay for
In Example 18.6-6, determine the following:(a) The expected number of idle cabs.(b) The probability that a calling customer will be next to last on the list.(c) The limit on the waiting list if it is desired to keep the waiting time in the queue to below 3.5 minutes.
For the 1M/M/c2:1GD//2 model, show the following:(a) The probability that a customer is waiting is r 1c - r2 pc.(b) The average number in the queue given that it is not empty is c 1c - r2 .(c) The expected waiting time in the queue for customers who must wait is 1 m1c - r2 .
Show that for the 1M/M/c2:1GD//2 model Lq =cr 1c - r22 pc
Show that pn for the 1M/M/12:1GD//2 model can be obtained from that of the 1M/M/c2:1GD//2 model by setting c = 1.
Prove that Ls = Lq + c starting with the definition Lq = gn = c + 11n - C2pn, where c is the average number of busy servers. Hence, show that c = leff m .
In the derivation of pn for the 1M/M/c2:1GD//2 model, indicate which part of the derivation requires the condition rc 6 1. Explain verbally the meaning of the condition.What will happen if the condition is not satisfied?
For the 1M/M/c2:1GD//2 model, Morse (1958, p. 103) shows that as rc S 1, Lq =r c - r Noting that rc S 1 means that the servers are extremely busy, use this information to show that the ratio of the average waiting time in queue in the 1M/M/c2:1GD//2 model to that in the 1M/M/12:1GD//2 model
In the United States, the use of single-line, multiple-server queues is common in post offices and in passenger check-in counters at airports. However, both grocery stores and banks (especially in smaller communities) tend to favor single-line, single-server setups, despite the fact that
Drake Airport services rural, suburban, and transit passengers. The arrival distribution for each of the three groups is Poisson with mean rates of 15, 10, and 20 passengers per hour, respectively. The time to check in a passenger is exponential with mean 6 minutes.Determine the number of counters
The U of A computer center is equipped with four identical mainframe computers. The number of users at any time is 25. Each user is capable of submitting a job from a terminal every 15 minutes, on the average, but the actual time between submissions is exponential.Arriving jobs will automatically
A small post office has two open windows. Customers arrive according to a Poisson distribution at the rate of 1 every 3 minutes. However, only 80% of them seek service at the windows. The service time per customer is exponential, with a mean of 5 minutes.All arriving customers form one line and
McBurger fast-food restaurant has 3 cashiers. Customers arrive according to a Poisson distribution every 3 minutes and form one line to be served by the first available cashier. The time to fill an order is exponentially distributed with a mean of 5 minutes.The waiting room inside the restaurant is
Customers arrive at Thrift Bank according to a Poisson distribution, with a mean of 45 customers per hour. Transactions per customer last about 5 minutes and are exponentially distributed. The bank wants to use a single-line multiple-teller operation, similar to the ones used in airports and post
Determine the minimum number of parallel servers needed in each of the following(Poisson arrival/departure) situations to guarantee that the operation of the queuing situation will be stable (i.e., the queue length will not grow indefinitely):(a) Customers arrive every 6 minutes and are served at
In the cab company example, suppose that the average time per ride is actually about 14.5 minutes, so that the utilization 1= l mc2 for the 2- and 4-cab operations increases to more than 96%. Is it still worthwhile to consolidate the two companies into one? Use the average waiting time for a ride
Consider Example 18.6-5.(a) Show that the remarkable reduction in waiting time by more than 50% for the consolidated case is coupled with an increase in the percentage of time the servers remain busy.(b) Suppose that calls for cab service in the consolidated company is increased to 20 customers per
Show that leff for 1M/M/12:1GD/N/2 can be computed from the formula leff = m1Ls - Lq2
Show that when r = 1 for 1M/M/12:1GD/N/2, the expected number in the system, Ls, equals N2. 1Hint: 1 + 2 + c + i = i1i + 12 2 .2
The probabilities pn of n customers in the system for an (M/M/1):1GD/5/2 are given in the following table:n 0 1 2 3 4 5 pn .399 .249 .156 .097 .061 .038 The arrival rate l is five customers per hour. The service rate m is eight customers per hour. Compute the following:*(a) Probability that an
Patients arrive at a 1-doctor clinic according to a Poisson distribution at the rate of 20 patients per hour. The waiting room does not accommodate more than 14 patients.Examination time per patient is exponential, with a mean of 8 minutes.(a) What is the probability that an arriving patient will
A cafeteria can seat a maximum of 50 persons. Customers arrive in a Poisson stream at the rate of 10 per hour and are served (one at a time) at the rate of 12 per hour.(a) What is the probability that an arriving customer will not eat in the cafeteria because it is full?(b) Suppose that three
The final assembly of electric generators at Electro is produced at the Poisson rate of 10 generators per hour. The generators are then conveyed on a belt to the inspection department for final testing. The belt can hold a maximum of 7 generators. An electronic sensor will automatically stop the
The time barber Joe takes to give a haircut is exponential with a mean of 12 minutes.Because of his popularity, customers usually arrive (according to a Poisson distribution) at a rate much higher than Joe can handle: six customers per hour. Joe will really feel comfortable if the arrival rate is
Consider the car wash facility of Example 18.6-4. Determine the number of parking spaces such that the percentage of cars that cannot find a space does not exceed 3%.
In Example 18.6-4, determine the following:(a) Probability that an arriving car will go into the wash bay immediately on arrival.(b) Expected waiting time until a service starts.(c) Expected number of empty parking spaces.(d) Probability that all parking spaces are occupied.(e) Percent reduction in
For the 1M/M/12:1GD//2, show that(a) The expected number in the queue, given that the queue is not empty, = 1 11 - r2 .(b) The expected waiting time in the queue for those who must wait = 1 1 m - l2.
For the 1M/M/12:1GD//2, derive the expression for Lq using the basic definition gn = 21n - 12pn.
In the 1M/M/12:1GD//2, give a plausible argument as to why Ls does not equal Lq + 1, in general. Under what condition will the equality hold?
Customers arrive at a one-window drive-in bank according to a Poisson distribution, with a mean of 10 per hour. The service time per customer is exponential, with a mean of 5 minutes. There are three spaces in front of the window, including the car being served. Other arriving cars line up outside
A fast-food restaurant has one drive-in window. Cars arrive according to a Poisson distribution at the rate of 2 cars every 5 minutes. The space in front of the window can accommodate at most 10 cars, including the one being served. Other cars can wait outside this space if necessary. The service
Cars arrive at the Lincoln Tunnel toll gate according to a Poisson distribution, with a mean of 90 cars per hour. The time for passing the gate is exponential with mean 38 seconds.Drivers complain of the long waiting time, and authorities are willing to reduce the average passing time to 30 seconds
Over the years, Detective Columbo, of the Fayetteville Police Department, has had phenomenal success in solving every single crime case. It is only a matter of time before any case is solved. Columbo admits that the time per case is “totally random,” but, on the average, each investigation will
John Macko is a student at Ozark U. He does odd jobs to supplement his income.Job requests come every 5 days on the average, but the time between requests is exponential. The time for completing a job is also exponential with mean 4 days.(a) What is the probability that John will be out of jobs?(b)
In Example 18.6-2, do the following.(a) Determine the percent utilization of the wash bay.(b) Determine the probability that an arriving car must wait in the parking lot prior to entering the wash bay.(c) If there are six parking spaces, determine the probability that an arriving car will find an
Solve Example 18.6-1 using the following data: number of parking spaces = 6, number of temporary spaces = 4, l = 10 cars per hour, and average parking time = 45 minutes.
In Example 18.6-1, do the following:*(a) Compute Lq directly using the formula gn = c + 11n - c2pn.(b) Compute Ws from Lq.*(c) Compute the average number of cars that will not be able to enter the parking lot during an 8-hr period.*(d) By definition, the average number of empty spaces can be

Showing 100 - 200 of 4739

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Last

Operations Research: An Introduction 10th Global Edition Hamdy A Taha - Solutions

Step by Step Answers