(20) The shifted demands for a turbine case are steady for the 6 weeks (50,50,60,60,50, 30). The setup cost is $300 and the holding cost is $3 per case per week. The production lead time is 3 weeks. You can find average production cycle times based on the values given. The forecasting errors can be captured by N(0,302). If the shortage cost is $15 4.1. (15) Please find the safety stock level. 4.2. (5) If the expected stock level at the beginning of the planning horizon is 25 , please fill out the lot release and inventory table similar to the one in the notes