Next, you will use the above information to build a simulation model. Below is some of the information you have collected from the production and sales department: Starting inventory is 3000 units. Sales are initially constant and remains at 1000 units/week. Starting workforce is 100 personnel. Each person can assemble 10 units/week i.e. productivity is 10. Target inventory is equivalent to 3 times the sales in that week. Time to adjust workforce is 3 weeks. Time to adjust inventory is 2 weeks. The below information will help you in simulating the model. Target production at any week is given by the sum of sales and inventory correction in that week. 'Net hire rate' depends on target workforce, workforce, and time to adjust workforce. The formula for 'net hire rate' is similar to 'inventory correction'. NOTE: The equation for 'inventory correction' and the 'Net hire rate' models the delay. Do not add any manual delay by jumping back more than 1 cell (1 week) in the past. A template excel sheet can be downloaded from here to help you in giving you a kick start in building the model.