Mechanical Engineering - Design and Management of Production Systems

Full exam

DMPS 18 June 2019 Prof. S. Terzi – Room L01 ID Code Student (Surname – Name) Personal Code «T» «CognomeNome » «Codice_persona » Exercise 1 - 7 points - ONLY WHAT YOU WRITE IN THE DEDICATED SPACES WILL BE EVALUATE D You are asked to design an automated transfer line that can perform the following processing cycle, using the “Ranked Positional W eighting” approach (also called Po sitional W eight Priority Index) following the Station Oriented Procedure and adopting MAXDUR as sub -criterion. Task Precedence Processing time (min) 1 - 0,31 2 - 0,5 3 1 0,3 4 1 0,24 5 1,2 0,12 6 3,4 0,33 7 5 0,29 8 6,7 0,38 9 7 0,25 10 8,9 0,45 Please, using a Theoretical Production Capacity (TPC) of 75 pieces/hours, compute the reference Cycle Time needed to balance the line. Then, draw the precedence diagra m of the production tasks and calculate as well the minimum number of needed works tations. Please, state clearly your solution ( allocating tasks in each single station according to the criteria specified above ) following the schema proposed . At the end , calculate the line efficiency . Cycle Time ______________ Precedence diagram Minimum number of workstations _____________________________________ DMPS 18 June 2019 Prof. S. Terzi – Room L01 ID Code Student (Surname – Name) Personal Code «T» «CognomeNome » «Codice_persona » Solution Task ti (min) PW (min) 1 0,31 2 0,5 3 0,3 4 0,24 5 0,12 6 0,33 7 0,29 8 0,38 9 0,25 10 0,45 1 2 3 Available Allocated Allocated Time Cumulative Allocated Time 4 5 6 Available Allocated Allocated Time Cumulative Allocated Time Efficiency _______________________________ DMPS 18 June 2019 Prof. S. Terzi – Room L01 ID Code Student (Surname – Name) Personal Code «T» «CognomeNome » «Codice_persona » Exercise 2 - 7 points - ONLY WHAT YOU WRITE IN THE DEDICATED SPACES WILL BE EVALUATE D MARCELLA CABASSI is an Italian brand that has been successfully associated with quality, craftsmanship and technical performance for the past five decades. The brand offers a wide range of beautiful, functional yet elegant products, including ready -to-wear clothing items. The company has a total turnover of 80M€ and is being known as one of th e front runners in the Italian luxury, mainly due to marketing, publicity and communication campaigns at the global level. Nevertheless, the company has some strategic targets for which some operational strategies must be redefined and some actions must be rejuvenated to accelerate the growth. MARCELLA CABASSI is considering to support their clothing line with accessories (leather bags) that would ultimately increase the business. The demand for leather b ags is estimated to be 50 Unit L oad/month and coefficient of variation of 0.05. All items can be outsourced from two of their most reliable suppliers. The first supplier proposes a contract based on fixed quantity w hile assuring the deliveries in 15 days, with a standard deviation of one day. The second supplier, on the other hand, offers a contract in accordance with fixed time model of two months, a delivery time of 10 days, with a standard deviation of one day. The purchasing cost of each UL accounts for 2000 €/UL and the cost of trans port as well as cargo handling operations accounts for 750€/order that is to be b orne by MARCELLA CABASSI. There are 21 working days per month for 11 months a year. Lastly, the opportunity cost of capital to be considered is 12% whilst the stock holding ra te accounting for 16%. Considering that safety stocks are required to ensure the avoidance of stock -out with a service level of 97.5 %, please fill the following table. Supplier 1 Supplier 2 EOQ: OL: ROP: SS: SS: AIL: AIL: Total cost: Total cost: % discount which will make the two suppliers indifferent: DMPS 18 June 2019 Prof. S. Terzi – Room L01 ID Code Student (Surname – Name) Personal Code «T» «CognomeNome » «Codice_persona » DMPS 18 June 2019 Prof. S. Terzi – Room L01 ID Code Student (Surname – Name) Personal Code «T» «CognomeNome » «Codice_persona » Exercise 3 - 7 points - ONLY WHAT YOU WRITE IN THE DEDICATED SPACES WILL BE EVALUATE D The Dancing Shoes Ltd designs and manufactures shoes. Starting from the forecasted sale for the year 2020, the sales manager, Mr Turner , asked the logistic department to evaluate the performance of some specific product s in the warehouse (product s from 1 t o 8) . Data related to the annual consumption (thousands of pieces), to annual stock level (thousands of pieces) and production cost (€ per piece) are available and reported in the Table. Moreover, some specific product s are particularly worrying Mr Turner, and he is asking for some further detailed analysis. 1. Determine the distribution of products using ABC -ABC technique (consumption and stock value). Use 75% and 90% as thresholds for both of them (place products where they develop the most part of their value) . 2. Product 1 and 2 are both fashionable sneakers, particularly appreciated by young people. Product 2 was introduced one year after Product 1 and since then the sales of 1 have been slightly diminish ing . Mr Turner wants to know which of the two products seems to have better inventory management, according to the STI index. Are there any actions for the management of Product 1 and 2 that you would suggest to Mr Turner? 3. Product 4 is a running shoe. The sales of 4 have been constant over the past years. However, given the planned dismission of Product 5, another running shoe, an increase in the sales of Product 4 is expected. Are there any actions for the management of Product 4 that you would suggest to Mr Turner? 4. Product 8 is shoelaces. They were produced for a particular model of shoes that w ere sold by the firm almost a decade ago and whose sales did not meet the expected value, leading to the dismission of the product. Are there any actions for the management of Product 8 that you would suggest to Mr Turner? Product Consumption (thousand s of p ieces ) Average stock level (thousands of p ieces ) Production cost (€/pc) 1 90 70 35 2 60 45 60 3 90 20 65 4 40 70 25 5 15 10 45 6 80 25 20 7 60 15 25 8 5 10 20 1. Determine the distribution of products using ABC -ABC technique Consumption (calculation and classes): DMPS 18 June 2019 Prof. S. Terzi – Room L01 ID Code Student (Surname – Name) Personal Code «T» «CognomeNome » «Codice_persona » Products distribution in ABC -ABC: Consumption A B C A Stock B C 2. STI for Product 1 and 2, comment and suggested actions STI Product 1 : Comment and suggested actions : STI Product 2 : 3. Suggested actions for Product 4 : 4. Suggested actions for Product 8 :