The following precedence diagram reflects three time estimates in weeks for each activity. Determine:
a. The expected completion time for each path and its variance.
b. The probability that the project will require more than 49 weeks.
c. The probability that the project can be completed in 46 weeks or less.
9-10-12 8 5-7-10 8-10-14 6 11 14-18-26 10.5-13-15.5 10 8-8-8 5-6-7 1 2 13-13-13 7-10-12 5 00 99-9 10-11-12 11-12-13 10-12-14 in
> What are some recent trends in supply chain management?
> Describe supplier certification and explain why it can be important.
> Discuss centralization versus decentralization in purchasing. What are the advantages of each?
> Describe how purchasing interacts with two other functional areas of an organization.
> Explain the importance of supply chain visibility.
> What are some of the main obstacles that must be overcome in converting from a traditional system to lean?
> What are some of the trade-offs that might be factors in designing a supply chain?
> Who in the organization is affected by a decision to shift from a traditional operations system to a lean system?
> Explain strategic partnering.
> What is meant by the term inventory velocity and why is this important? What is information velocity, and why is it important?
> Why might a person wish to be involved with a critical path activity? What are some of the reasons one might have for not wanting this association?
> Explain the increasing importance of the procurement function.
> What is the bullwhip effect, and why does it occur? How can it be overcome?
> Explain why each of these is critical for a successful supply chain operation: a. Integrated technology b. Information sharing c. Trust among trading partners d. Real-time information availability e. Event-response capability f. Procurement g. Risk manag
> Select three of the examples of unethical behavior in section 15.5, other than those that violate basic human rights, and indicate which principle in Table 15.2 would be violated.
> From a systems viewpoint, what are some of the environmental issues involved in a decision by a company to outsource manufacturing operations to a foreign country?
> Given the complexities and risks involved with supply chains, might it make sense for a business organization to vertically integrate and be its own supply chain?
> Some customers of Internet businesses can avoid paying state sales taxes on purchases if the Internet businesses don’t have a physical presence in their state. However, more states are enacting laws to collect taxes. What impact might this have on the cl
> What trade-offs are involved in shifting from a traditional operations system to a lean system for a manufacturing firm? For a service firm?
> A JIT system uses kanban cards to authorize movement of incoming parts. In one portion of the system, a work center uses an average of 100 parts per hour while running. The manager has assigned an inefficiency factor of .20 to the center. Standard contai
> A manager wants to determine the number of containers to use for incoming parts for a kanban system to be installed next month. The process will have a usage rate of 80 pieces per hour. Because the process is new, the manager has assigned an inefficiency
> Compute the takt time for a service system that intended to perform a standardized service. The system will have a total work time of 440 minutes per day, two 10-minute breaks, and an hour for lunch. The service system must process 90 jobs a day.
> Give three examples of unethical behavior involving lean operations, and state the relevant ethical principle that would be violated.
> What cycle time would match capacity and demand if demand is 120 units a day, there are two shifts of 480 minutes each, and workers are given three half-hour breaks during each shift, one of which is for lunch or dinner?
> Why might a probabilistic estimate of a project’s completion time based solely on the variance of the critical path be misleading? Under what circumstances would it be acceptable?
> Compute the takt time for a system where the total time per shift is 480 minutes, there is one shift, and workers are given two 15-minute breaks and 45 minutes for lunch. Daily demand is 300 units.
> Determine the number of cycles per day and a production quantity per cycle for this set of products that achieves fairly level production: Product Daily …………………Quantity F ……………………………………………...9 G ……………………………………………...8 H ………………………………………………5 K ………………………………
> Given this set of daily service operations, and assuming a processing order of A-B-C-D-E: a. Give one reason that each arrangement might be preferred over the other. b. Determine the number of repetitions for each service if four cycles are used. c. Dete
> Determine the number of cycles per day and the production quantity per cycle for this set of vehicles: Product ……………………….Daily Quantity A …………………………………………………..21 B ………………………………………………….12 C …………………………………………………..3 D ………………………………………………….15 Use the sequenc
> A machine cell uses 200 pounds of a certain material each day. Material is transported in vats that hold 20 pounds each. Cycle time for the vats is about two hours. The manager has assigned an inefficiency factor of .08 to the cell. The plant operates on
> Describe the philosophy that underlies JIT (i.e., what is JIT intended to accomplish?).
> Name and explain briefly two ways that technology has had an impact on project management.
> Reconsider the network diagram of Problem 1a. Suppose that after 12 weeks, activities 1-2, 1-3, and 2-4 have been finished; activity 2-5 is 75 percent finished; and activity 3-6 is half finished. How many weeks after the original start time should the pr
> For each of the problems listed, determine the following quantities for each activity: the earliest start time, latest start time, earliest finish time, latest finish time, and slack time. List the critical activities, and determine the expected duration
> a. Develop a list of activities and their immediate predecessors similar to the lists in this problem for this diagram: b. Construct an activity-on-arrow precedence diagram for each of the following cases. Note that each case requires the use of a dumm
> List the main advantages of PERT. List the main limitations.
> Prepare a Gantt chart for each of the following in the style of the chart shown in section 17.5. a. The bank location problem (see Figure 17.4). Hint: Use the early start (ES) times given in Table 17.3. b. Solved Problem number 2.
> Chris received new word processing software for her birthday. She also received a check, with which she intends to purchase a new computer. Chris’s college instructor assigned a paper due next week. Chris decided that she will prepare the paper on the ne
> 1. For each of the following network diagrams, determine both the critical path and the expected project duration. The numbers on the arrows represent expected activity times. a. AOA diagram b. AON diagram c. AOA diagram d. AON diagram 9 10 12
> Create a risk matrix for this project: Explain your reasoning for your placement of the events Weather problems and Funding delays. Event Cost ($000) Probability Equipment breakdown Vendor is late with key segment 40 .20 200 .60 Subcontractor has l
> Create a risk matrix in the style of Figure 17.13 for this project. Use a vertical scale of $0 to $80. Which event should the project manager be most concerned about? Event Probability Cost ($000) 1 25 15 .35 25 3 .20 55 4 .80 10 .10 77 6 .40 55 7 .
> Given the following table, construct a network diagram, either AOA or AON. Times are in days. a. Determine the expected duration of the project. b. Compute the probability that the project will take at least 18 days. Path Activity Time Estimates 4-5
> What is the ultimate goal of a lean system? What are the supporting goals? What are the building blocks?
> Chuck’s Custom Boats (CCB) builds luxury yachts to customer order. CCB has landed a contract with a mysterious New York lawyer (Mr. T). Relevant data are shown on the next page. The complication is that Mr. T wants delivery in 32 weeks
> A construction project has indirect costs totaling $40,000 per week. Major activities in the project and their expected times in weeks are shown in this precedence diagram. Crashing costs for each activity are: a. Determine the optimum timeâ
> The project manager of a task force planning the construction of a domed stadium had hoped to be able to complete construction prior to the start of the next college football season. After reviewing construction time estimates, it now appears that a cert
> Identify the term being described for each of the following: a. A sequence of activities in a project. b. The longest time sequence of activities in a project. c. Used when two activities have the same starting and finishing points. d. The difference in
> Here is a list of activity times for a project as well as crashing costs for its activities. Determine which activities should be crashed and the total cost of crashing if the goal is to shorten the project by three weeks as cheaply as possible. First co
> A project manager has compiled a list of major activities that will be required to install a computer information system in her firm. The list includes estimated completion times for activities and precedence relationships. a. Construct a network diag
> The project described in the following table is scheduled to be completed in 11 weeks. Construct a network diagram using AOA or AON. Then answer the following questions: a. If you were the manager of this project, would you be concerned? Explain. b. If t
> Construct a network diagram for the information in the following table. Use either AOA or AON (see Example 5 for either type). What is the probability that the project will take more than 10 weeks to complete if the activity means and standard deviations
> The new director of special events at a large university has decided to completely revamp graduation ceremonies. Toward that end, a PERT chart of the major activities has been developed. The chart has five paths with expected completion times and varianc
> Three recent college graduates have formed a partnership and have opened an advertising firm. Their first project consists of activities listed in the following table. a. Draw the precedence diagram. b. What is the probability that the project can be com
> What are the key advantages of using project management software?
> Give some examples of ethical issues that may arise on projects. What can a project manager do to minimize such issues?
> Give three examples of unethical conduct involving projects and the ethical principle each one violates.
> Project management techniques have been used successfully for a wide variety of efforts, including the many NASA space missions, huge construction projects, implementation of major systems such as ERP, production of movies, development of new products an
> Would you expect that many people would turn down a chance to join a project organization, as Bert Mill did?
> In consideration of Robert Linderman’s letting the division managers know that the project manager would be asking for some of their key people, why would Conway have any difficulty in getting the ones he wanted?
> What could Linderman Industries have done to assure go d jobs for the people coming off Project Mexicano, including Carl Conway, the project manager?
> Why would Conway take his problem with the engineering vice president to Linderman and have it resolved in his favor, yet back down in two disputes with the manufacturing vice president?
> How has technology had an impact on scheduling?
> Some key elements of production systems are listed in Table 14.3. Explain briefly how lean systems differ from traditional production systems for each of those elements.
> What general trade-offs are involved in sequencing decisions? In scheduling decisions?
> What are the main benefits of a lean system?
> The following table shows orders to be processed at a machine shop as of 8:00 a.m. Monday. The jobs have different operations they must go through. Processing times are in days. Jobs are listed in order of arrival. a. Determine the processing sequence at
> Using the information presented in the following table, identify the processing sequence that would result using (1) FCFS, (2) SPT, (3) EDD, and (4) CR. For each method, determine (1) average job flow time, (2) average job tardiness, and (3) average numb
> The following table contains information concerning four jobs that are awaiting processing at a work center. a. Sequence the jobs using (1) FCFS, (2) SPT, (3) EDD, and (4) CR. Assume the list is by order of arrival. b. For each of the methods in part a
> Use the assignment method to obtain a plan that will minimize the processing costs in the following table under these conditions: a. The combination 2-D is undesirable b. The combinations 1-A and 2-D are undesirable
> 4. Develop an assignment plan that will minimize processing costs, given the information shown, and interpret your answer.
> Assign trucks to delivery routes so that total costs are minimized, given the cost data shown. What is the total cost?
> Rework Problem 1, treating the numbers in the table as profits instead of costs. Compute the total profit.
> Use the assignment method to determine the best way to assign workers to jobs, given the following cost information. Compute the total cost for your assignment plan.
> List the steps in risk management.
> Determine the minimum number of workers needed, and a schedule for the following staffing requirements, giving workers two consecutive days off per cycle (not including Sunday).
> Determine the minimum number of workers needed, and a schedule for the following staffing requirements, giving workers two consecutive days off per cycle (not including Sunday).
> Contrast push and pull methods of moving goods and materials through production systems.
> Determine the minimum number of workers needed, and a schedule for the following staffing requirements, giving workers two consecutive days off per cycle (not including Sunday).
> Given the following data on inputs and outputs at a work center, determine the cumulative deviation and the backlog for each time period. The beginning backlog is 7.
> Given this information on planned and actual inputs and outputs for a service center, determine the work backlog for each period. The beginning backlog is 12 hours of work. The figures shown are standard hours of work.
> The following table contains order-dependent setup times for four jobs. For safety reasons, job C cannot follow job A, nor can job A follow job C. Determine the processing sequence that will minimize the total setup time. (Hint: There are 12 alternatives
> The following table contains order-dependent setup times for three jobs. Which processing sequence will minimize the total setup time?
> The following table contains order-dependent setup times for three jobs. Which processing sequence will minimize the total setup time?
> The Budd Gear Co. specializes in heat-treating gears for automobile companies. At 8:00 a.m., when Budd’s shop opened today, five orders (listed in order of arrival) were waiting to be processed. a. If the earliest due date rule is use
> Explain the term project champion and list some ways to keep a champion involved with the project.
> What are the benefits and risks of small lot sizes?
> What might Stephanie determine as the best production quantity per cycle for each day of the week?
> Suppose your manager presents you with the following information about machines that could be used for a job, and wants your recommendation on which one to choose. The specification width is 48 mm. In this instance, you can narrow the set of choices, but
> Briefly describe computer-assisted approaches to production.
> A producer of inkjet printers is planning to add a new line of printers, and you have been asked to balance the process, given the following task times and precedence relationships. Assume that cycle time is to be the minimum possible. a. Do each of th
> Given the following list of processes, the standard deviation for each, and specifications for a job that may be processed on that machine, determine which machines are capable of performing the given jobs. Process Standard Deviation (in.) Job Speci
> A manager wants to assign tasks to workstations as efficiently as possible and achieve an hourly output of four units. The department uses a working time of 56 minutes per hour. Assign the tasks shown in the accompanying precedence diagram (times are in
> Consider an assembly line such as the burrito assembly line at Chipotle Mexican Grill. During slow times of the day, one server can handle assembly, but during very busy times, having many servers would be prudent. Explain why either approach wouldn’t wo
> A manager wants to assign tasks to workstations as efficiently as possible and achieve an hourly output of 33 units. Assume the shop works a 60-minute hour. Assign the tasks shown in the accompanying precedence diagram (times are in minutes) to workstati
> An assembly line with 17 tasks is to be balanced. The longest task is 2.4 minutes, and the total time for all tasks is 18 minutes. The line will operate for 450 minutes per day. a. What are the minimum and maximum cycle times? b. What range of output is
> Burger Prince buys top-grade ground beef for $1.00 per pound. A large sign over the entrance guarantees that the meat is fresh daily. Any leftover meat is sold to the local high school cafeteria for 80 cents per pound. Four hamburgers can be prepared fro
> Rebalance the assembly line in Problem 7. This time, use the longest operation time heuristic. Break ties with the most following tasks heuristic. What is the percentage idle time for your line?
> Ten labs will be assigned to the circular layout shown. Recalling a similar layout’s congestion in the halls, the new lab manager has requested an assignment that will minimize traffic between offices. Department 1 must be at location A
> Develop a process layout that will minimize the total distance traveled by patients at a medical clinic, using the following information on projected departmental visits by patients and distance between locations. Assume a distance of 35 feet between the
> Eight work centers must be arranged in an L-shaped building. The locations of centers 1 and 3 are assigned as shown in the accompanying diagram. Assuming transportation costs are $1 per load per meter, develop a suitable layout that minimizes transportat