EPT2601/101/3/2021

Tutorial Letter 101/3/2021 Engineering Production Technology II EPT2602 Assignment 2 Semesters 1 and 2 Department of Mechanical and Industrial Engineering This tutorial letter contains important information about your module. BARCODE 2 SEMESTER 1 & 2 ASSIGNMENT 2 QUESTION 1 1.1 Describe the policies based on the ABC analysis of inventory. (3) 1.2 Describe what can happen if an organisation does not monitor their inventory. (3) 1.3 Discuss the risks associated with outsourcing. (5) 1.4 List and briefly describe the three (3) stages of the vendor selection process. (6) 1.5 List and briefly describe the constraints that will influence the allocation of work activities on workstations. (6) [23] QUESTION 2 2.1 Describe Synchronous Manufacturing. (2) 2.2 Discuss about Bottleneck/s that may be present in a manufacturing process, use examples to supplement your answer. (6) 2.3 When conducting assembly line balancing, it said that it will be unrealistic to assume human beings will have a constant time for activities as compared to machines at stations. Explain why when human beings are performing the work there will be variability in the activity times. (4) 2.4 A company that manufactures brass valve has an annual demand of 44 800 units. The carrying cost is R70 per unit per year, and the setup cost is R120 per setup. The company is able to produce 200 units per day, and is in operation 320 days a year. Calculate the following: 2.4.1 The optimal production order quantity. (3) 2.4.2 The number of setups the company will make in a year with the optimal policy. (2) 2.4.3 The maximum number of brass valve that will be in the inventory. (2) EPT2602/101/3/2021 3 2.4.4 The annual inventory costs (setup + holding costs). (4) [23] QUESTION 3 3.1 List the disadvantages of JIT (Just In Time) in comparison to Synchronous Manufacturing. (8) 3.2 The Operations Manager of Nesa electronics prides herself on excellent assembly line balancing. She has been told that the company needs to complete 60 instruments per 12 hour work day. The assembly activities, the activity times as well as the precedence relationship/s are shown in the table below: Activity Predecessor/s Time (Minutes) A None 4 B None 4 C A,B 6 D C 6 E C 5 F D, E 8 G F 3 H G 9 I F,G,H 1 J I 5 K G,H,I,J 2 L K 10 3.2.1 Calculate the Positional Weight of each work activity. (6) 3.2.2 Use the Ranked Positional Weight Method, and design an assembly line to meet the demand. (Show all calculations including the cumulative station times and the unassigned station times). (12) 3.2.3 Calculate the balancing loss for this assembly line. (3) [29] 4 QUESTION 4 4.1 Discuss the Kanban system. (6) 4.2 Describe the three stages of a product life cycle as presented in the reliability bathtub curve. (6) 4.3 A company that produces laptop computers is moving to Kanban to support their assembly line. Determine the size of the Kanban for their subassemblies and the number of Kanbans needed given the following information: (7) Daily demand 200 units Daily Production 350 units Setup cost R90 per setup Holding cost R42 per unit per year Lead Time 3 days Safety Stock 2 day of production Number of workdays a year 250 days 4.4 A company has inventory turnover of eight times per year and would like to reduce their component lot sizes to three (3) days of production. A production engineer in the company has prepared the following data for this operation: Annual Demand 30 000 units Daily production 160 units Desired lot size 3 days of production Holding cost R85 per unit per year Setup labour cost R160 per hour Working days per year 250 days 4.4.1 Calculate the minutes of setup the company should aim at for this component. (6) [25] EPT2602/101/3/2021 5 QUESTION 5 5.1 List any two (2) big losses an organisation would want to eliminate and/or reduce through Total Productive Maintenance program/s. Provide two (2) examples for each loss. (6) 5.2 A sample of eighty (80) semiconductors were tested in an operating light test for 2000 hours. Out of the eighty semiconductors, ten (10) semiconductors were not repairable and failed as follows: one conductor failed at 1200 hours; two conductors failed at 1440 hours; two conductors failed at 1600 hours; two conductors failed at 1700 hours; and three more conductors failed at 1900 hours. Calculate the following: 5.2.1 Percentage of failures. (2) 5.2.2 Number of failures per unit-hour. (3) 5.2.3 Number of failures per unit-year (2) 5.3 Pretoria Private Hospital has experienced breakdowns with their ambulances in the past. Over the past 18 months, the ambulances have broken down at the rate indicated in the table below. Each time an ambulance breaks down; the hospital loses an estimated R2000 in outsourcing ambulance services and service related expenses. The hospital has an option of purchasing a service contract for preventive maintenance at a price of R4000 per month. Even if the hospital contracts preventive maintenance, there will still be breakdowns, averaging 1 breakdown a month. Number of Breakdowns 0 1 3 4 5 2 Number of Months in which Breakdown Occurred 6 5 3 1 2 1 5.3.1 Should the company carry with the current maintenance policy or should they implement preventive maintenance program? (Show all calculations) (7) [20] 6 QUESTION 6 6.1 A company that manufactures car audios has summarized the price lists from two (2) potential suppliers for a subcomponent. Expected demand is 50,000 units annually, the ordering cost is R62 per order and the inventory holding cost is estimated to be 20% of the unit cost. Which supplier should the company select and what order quantity is best to minimize total costs? (Show all calculations) (15) Supplier A Supplier B Quantity Price Quantity Price 1-199 R640 1-149 R640 200-399 R600 150-399 R610 400+ R580 400+ R593 [15] TOTAL MARKS = 135 Unisa 2021