A small warehouse provides work-in-process storage for a manufacturing facility that produces four different part types. The part-type percentages and inventory costs per part are: Inventory Cost Part Type Percentage Per Part 1 20 $5.50 2 30 $6.50 3 30 $8.00 4 20 $10.50 The interpretation of “inventory cost per part” is as follows. Each part in inventory contributes an amount from the last column of the above table to the total cost (value) of inventory being held at the moment. For instance, if the current inventory is three units of Part 1, none of Part 2, f ve of Part 3, and one of Part 4, then the current inventory cost is 3 × $5.50 + 0 × $6.50 + 5 × $8.00 + 1 × $10.50 = $67.00. As parts arrive and depart, as described below, this inventory cost will rise and fall. kel01315_ch05_207-278.indd 273 05/12/13 3:28 PM 274 Chapter 5 Parts arrive with TRIA(1.25, 2.0, 2.8) interarrival times (all times are in minutes); the f rst part arrives at time 0. Two cranes store and retrieve parts with a travel time of UNIF(1.25, 2.9), each way. Requests for part removal (think of them as customers) arrive with TRIA(1.25, 2.0, 2.8) interarrival times, independently of the arrival process for the parts, and the f rst request arrives at time 0. If no part is available, the request is not f lled. All part requests are given priority over part storages in terms of getting the use of a crane, and priority is given to retrieving based on the highest part cost. For part arrivals, increment the inventory cost upon arrival, and increment the total number of parts in inventory after the part is stored. For part requests, decrement the total number of parts in inventory as soon as you know there is a part to retrieve, and decrement the inventory cost after the part is retrieved. Run your model for a single replication of length 5,000 minutes starting with four of each part type in the warehouse. Collect statistics on the crane utilization, the average inventory cost, the average number of each part type in the warehouse, and the number of unf lled requests due to having no parts of the requested type. HINTS: Use index variables for part inventory and per-part cost. (Note that you can use the “Other” option in the Assign module when assigning to index variables, or you could select the Type in the Assign module to be Variable Array [1D].) Use the Discrete distribution to determine the part type and the Statistic data module (with Type selected as Time-Persistent) to collect some of the required statistics.