Operations Management
13th Edition
ISBN: 9780135173626
Author: HEIZER, Jay, RENDER, Barry, Munson, Chuck
Publisher: Pearson,
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Textbook Question
Chapter 3, Problem 20P
The estimated times and immediate predecessors for the activities in a project at Howard Umrah’s retinal scanning company are given in the following table. Assume that the activity times are independent.
- a. Calculate the expected time and variance for each activity.
- b. What is the expected completion time of the critical path? What is the expected completion time of the other path in the network?
- c. What is the variance of the critical path? What is the variance of the other path in the network?
- d. If the time to complete path A–C is
normally distributed , what is the probability that this path will be finished in 22 weeks or less? - e. If the time to complete path B–D is normally distributed, what is the probability that this path will be finished in 22 weeks or less?
- f. Explain why the probability that the critical path will be finished in 22 weeks or less is not necessarily the probability that the project will be finished in 22 weeks or less.
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The estimated times and immediate predecessors for the activities in a project a t George Kyparis's retinal scanning company are given in the following table. Assume that the activitytimes are independent. a) Calculate the expected time and variance for each activity.b) What is the expected completion time of the critical path?What is the expected completion time of the other path in the network?c) What is the variance of the critical path? Wha t is the variance of the other path in the network?d) If the time to complete path A-C is normally distributed, what is the probability that this path will be fini shed in 22 weeks or less?e) If the time to complete path B- D is normally distributed, what is the probability that this path will be finished in 22 weeks or less?f) Explain why the probability that the critical path will be finished in 22 weeks or…
Could you please solve d, e and f. Thanks
The estimated times and immediate predecessorsfor the activities in a project at George Kyparis’s retinal scan-ning company are given in the following table. Assume thatthe activity times are independent.
a) Calculate the expected time and variance for each activity.b) What is the expected completion time of the critical path?What is the expected completion time of the other path inthe network?c) What is the variance of the critical path? What is the vari-ance of the other path in the network?d) If the time to complete path A–C is normally distributed,what is the probability that this path will be finished in22 weeks or less?e) If the time to complete path B–D is normally distributed,what is the probability that this path will be finished in22 weeks or less?f) Explain why the probability that the critical path will befinished in 22 weeks or less is not necessarily the probabil-ity that the project will be finished in 22 weeks or less.
Chapter 3 Solutions
Operations Management
Ch. 3 - Prob. 1EDCh. 3 - Give an example of a situation in which project...Ch. 3 - Explain the purpose of project organization.Ch. 3 - What are the three phases involved in the...Ch. 3 - What are some of the questions that can be...Ch. 3 - Define work breakdown structure. How is it used?Ch. 3 - What is the use of Gantt charts in project...Ch. 3 - What is the difference between an...Ch. 3 - What is the significance of the critical path?Ch. 3 - What would a project manager have to do to crash...
Ch. 3 - Describe how expected activity times and variances...Ch. 3 - Define earliest start, earliest Finish, latest...Ch. 3 - Students are sometimes confused by the concept of...Ch. 3 - What are dummy activities? Why are they used in...Ch. 3 - What are the three time estimates used with PERT?Ch. 3 - Would a project manager ever consider crashing a...Ch. 3 - How is the variance of the total project computed...Ch. 3 - Describe the meaning of slack, and discuss how it...Ch. 3 - How can we determine the probability that a...Ch. 3 - Name some of the widely used project management...Ch. 3 - Prob. 20DQCh. 3 - Draw the activity-on-node (AON) project network...Ch. 3 - Given the activities whose sequence is described...Ch. 3 - 3.5 Using AOA, diagram the network described below...Ch. 3 - Task time estimates for the modification of an...Ch. 3 - The activities needed to build a prototype laser...Ch. 3 - The activities described by the following table...Ch. 3 - A renovation of the gift shop at Orlando Amway...Ch. 3 - Kelle Carpet and Trim installs carpet in...Ch. 3 - The following is a table of activities associated...Ch. 3 - What is the minimum cost of crashing the following...Ch. 3 - Three activities are candidates for crashing on a...Ch. 3 - Development of Version 2.0 of a particular...Ch. 3 - The estimated times and immediate predecessors for...Ch. 3 - Rich Cole Control Devices, Inc., produces...Ch. 3 - Four Squares Productions, a firm hired to...Ch. 3 - Using PERT, Adam Munson was able to determine that...Ch. 3 - Clark Products makes pizza ovens for commercial...Ch. 3 - Prob. 1PCh. 3 - Prob. 2PCh. 3 - Prob. 3PCh. 3 - Prob. 4PCh. 3 - Prob. 8PCh. 3 - Prob. 13PCh. 3 - Prob. 15PCh. 3 - Prob. 17PCh. 3 - Prob. 24PCh. 3 - Prob. 25PCh. 3 - Prob. 28PCh. 3 - Prob. 33PCh. 3 - Project Management at Arnold Palmer Hospital Video...Ch. 3 - The equivalent of a new kindergarten class is born...Ch. 3 - The equivalent of a new kindergarten class is born...Ch. 3 - The equivalent of a new kindergarten class is born...Ch. 3 - At the Hard Rock Cafe, like many organizations,...Ch. 3 - At the Hard Rock Cafe, like many organizations,...Ch. 3 - At the Hard Rock Cafe, like many organizations,...Ch. 3 - At the Hard Rock Cafe, like many organizations,...
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, operations-management and related others by exploring similar questions and additional content below.Similar questions
- Consider a project that has been modeled as in the table below. Part a) Draw the PERT/CPM network for this project and determine the project’s expected completion time μP and its critical path. Part b) Suppose the standard deviations of the activity durations are σA = 2, σB = 1, σC = 0, σD = 2, σE = 3, and σF = 0. Then please estimate the standard deviation of the overall project’s standard deviation σP . Part c) Suppose for the standard Normal random variable Z, we know P[−1 ≤ Z ≤ +1] ' 68%, P[−2 ≤ Z ≤ +2] ' 95%, and P[−3 ≤ Z ≤ +3] ' 99.7%. Then, approximately what time T is one for which there is only a less than 2.5% chance for the completion time to beat (be shorter than)? *Please answer a-c and type your work and answers or write them neatly please* Thank youarrow_forwardConsider a project that has been modeled as in the table below. Part a) Draw the PERT/CPM network for this project and determine the project’s expected completion time μP and its critical path. Part b) Suppose the standard deviations of the activity durations are σA = 2, σB = 1, σC = 0, σD = 2, σE = 3, and σF = 0. Then please estimate the standard deviation of the overall project’s standard deviation σP . Part c) Suppose for the standard Normal random variable Z, we know P[−1 ≤ Z ≤ +1] ' 68%, P[−2 ≤ Z ≤ +2] ' 95%, and P[−3 ≤ Z ≤ +3] ' 99.7%. Then, approximately what time T is one for which there is only a less than 2.5% chance for the completion time to beat (be shorter than)? *Please answer a-c and either type your work and answers or write them neatly showing each step, please* NO EXCEL Thank you!arrow_forwardDave Fletcher was able to determine the activity times for constructing his laser scanning machine. Fletcher would like to determine ES, EF, LS, LF, and slack for each activity. The total project completion time and the critical path should also be determined. Here are the activity times: Activity Time (weeks) Immediate Predecessor(s) Activity Time (weeks) Immediate Predecessor(s)A 7 - E 4 BB 8 - F 7 BC 4 A G 11 C, ED 1 A H 6 D , F Dave's earliest start (ES) and earliest finish (EF) are: Activity ES EF A 0 7 B 0 8 C 7 11 D 7 88 E 8 12 Part 7 F ? ? G ? ? H ? ?arrow_forward
- Dave Fletcher was able to determine the activity times for constructing his laser scanning machine. Fletcher would like to determine ES, EF, LS, LF, and slack for each activity. The total project completion time and the critical path should also be determined. Here are the activity times: O Activity Time (weeks) Immediate Predecessor(s) Activity Time (weeks) Immediate Predecessor(s) E F A B C D Dave's earliest start (ES) and earliest finish (EF) are: 5 8 00 2 2 Activity HOT G ES Н EF 5 5 5 10 7 B B C, E D.Farrow_forwardDave Fletcher was able to determine the activity times for constructing his laser scanning machine. Fletcher would like to determine ES, EF, LS, LF, and slack for each activity. The total project completion time and the critical path should also be determined. Here are the activity times: Activity Time (weeks) Immediate Predecessor(s) Activity Time (weeks) Immediate Predecessor(s) A 7 − E 5 B B 8 − F 6 B C 4 A G 11 C, E D 3 A H 7 D , F Part 2 Dave's earliest start (ES) and earliest finish (EF) are: Part 3 Part 4 Part 5 Part 6 Part 7 Part 8 Part 9 Part 10 Dave's latest start (LS) and latest finish (LF) are:…arrow_forwardDave Fletcher was able to determine the activity times for constructing his laser scanning machine. Fletcher would like to determine ES, EF, LS, LF, and slack for each activity. The total project completion time and the critical path should also be determined. Here are the activity times: Activity Time (weeks) Immediate Predecessor(s) Activity Time (weeks) Immediate Predecessor(s) A 7 − E 4 B B 6 − F 5 B C 4 A G 10 C, E D 2 A H 8 D , F Part 2 Dave's earliest start (ES) and earliest finish (EF) are: Part 3 Part 4 Part 5 Part 6 Part 7 Part 8 Part 9 Part 10 Dave's latest start (LS) and latest finish (LF) are:…arrow_forward
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- Consider the project described in the table below: Activity Duration A B C D E F G H 9 4 8 8 5 7 4 6 OEST-9 and LCT = 15 OEST=9 and LCT = 13 Immediate Predecessor What is the earliest start time (EST) and latest completion time (LCT) of activity B? OEST=9 and LCT = 20 OEST-9 and LCT-17 - A A A B B,C C,D E,F,Garrow_forwardA project has the activity duration and cost information indicated in the table where all times are in weeks. What is the total cost for completing this project in 50 days? Activity Predecessor Normal Time Normal Cost Crash Time Crash Cost A -- 8 $12,000 5 $21,000 B A 12 $20,000 9 $30,000 C A 15 $24,000 10 $60,000 D B 3 $10,000 2 $15,000 E C 9 $17,000 6 $34,000 F E 7 $5,000 6 $6,000 G D 8 $14,000 6 $20,000 H A 12 $22,000 10 $30,000 I H 6 $50,000 5 $55,000 J F, G, I 11 $33,000 9 $50,000arrow_forwardConsider the following PERT time estimates: a. Draw a network for this project and determine the critical path based on the most likely times by inspection.b. Assuming that the critical path is the one you identified in part (a), what is the probability that the project will be completed before 28weeks? Before 32 weeks?c. Assuming that the critical path is the one you identified in part (a), how many weeks are required to complete the project with probability .95?arrow_forward
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