KIW Ltd currently orders Material B in batches of 2,500 kgs. Material B is consumed at a steady, known rate over the company's planning horizon of one year. The current usage is 40,000 kgs per annum. The costs of ordering Material B have been calculated at $300 per order. Each order is received and checked by an employee engaged in using B in production who generates a contribution of $90 per hour when not involved in materials checks. The stock check takes five hours. Holding costs amount to $15 per unit per annum.

The supplier of material B has very recently offered KIW a quantity discount of $0.24 per kg on the current price of $24, for all orders of 4,000 or more kgs of  Material B.

Required

(a)   Calculate the annual cost of the current ordering policy.                                      

(b)  Calculate the optimal order quantity of material B, ignoring the quantity discount;

(c)   Evaluate whether KIW should continue with the current ordering policy, order the economic order quantity or take advantage of the discount by ordering in batches of 4,000 kgs.                                                                                                                        

(d)  Critically discuss the limitations of the Economic Order Quantity model as a way of managing stock.                                                                                                    

e)   Specify the circumstances in which, a firm, although being able to determine the Economic Order Quantity, might choose a different re-order quantity.