Management Engineering - Operations Management

Second partial exam

Operations Management Exam – 3 July 2023 – Prof. Portioli, Rossini, Taisch O PERATIONS M ANAGEMENT EXAM Prof. Alberto Portioli Staudacher, Marco Taisch, Matteo Rossini July 3rd , 202 3 LEAN Exercise ( 13 points) Leather Lab s.r.l is one of the most important producer in Italy for wallet . The range of this product family is composed of 20 standard variants: 10 different colors and 2 different type s of material s. Leather Lab s.r.l produces also customized wallet based on customer requests and the range for this special product is unlimited . Each tailored wallet is different from the other , for this reason every customized wallet are made in a unitary batches with a dedicated setup for every production stage . Customers require all variants of standard products every day. The average demand for the company is 40 units/day. The daily demand is divided in 85% of standard wallet and 15 % of special wallet . The demand , both for standard product s and special products, is affected by variability (+/ - 10 % daily base) . The costumer s send order s for standard wallet ones per day , and they want to receive the order within the same day. On the other hand the orders for customized wallets are collect ed monthly. The company deliver s customized wallet two times per week. The company work s on shift s (8 hours per shift with 2 breaks of 15 minutes per shift) 5 days per week. Production process (there are no scraps): The production system is composed by 4 departments decoupled by stocks: Leather tanning phase – In this stage , the leather for the wallet is elaborated . The machine need s to do a setup every time a material is change d. Only one operator supervises the machine . Color phase – In this stage , 2 ope rators work in parallel performing manual activities. The operators need to make a setup every time they change a color . This stage is half dedicat e to this product family. Sew phase – In this stage , one operator manually sew s different parts of the wallet together. The operator need s to perform a set up every time he stitches wallet with a different material. Packaging phase – In this stage , an operator manually check the features of every wallet and put in an appropriate pack . After the production process there is a shipping area, where the production and control department send s daily plan for the shipment . A raw material stock upstream in the first stage covers 20 days of customer demand. Every week, the first stage informs th e production control about the raw material inventory level. The customer placing orders daily and a for 30/60 days forecast. The production control function issues a weekly production plan for each stage. The production control places a raw materials order to the supplier twice per month and sends a for 30/60 days forecast. The supplier delivers the day after the company order. Q1) ( 2,5 points) Draw the current state map for the production of credit card s. Q2) (1,5 points) Compute di EPE for Standard product in the sew phase. Q3) ( 9 points) Create a future state of the system (answering the first six questions of the future state) . The target for the improvements are: ensure that the company is able to both deliver 6 customized wallet every day in unitary batch es and fulfill the demand of standard products (in volume and mix) in maximum to 2 days in each stage . Phases Cycle Time for single resource (min ) Changeover (min.) Availability (%) Inventory (downstream) The Setup is done when changes (for standard product) Shifts Leather tanning phase 15 30 90 500 Material 2 Color phase 8 10 100 55 0 Color 1 Sew phase 2 20 100 600 Material 1 Packaging phase 3 0 99 650 No setup 1