Presentation on theme: "Master Scheduling and Rough-Cut Capacity Planning"— Presentation transcript:
1Master Scheduling and Rough-Cut Capacity Planning ISQA 459/559Mellie Pullman
2Learning ObjectivesExplain the role & objectives of a master production scheduleExplain the organizational links to master production schedulingDevelop a master production scheduleExplain rough-cut capacity planningCalculate available-to-promise quantitiesDescribe time fence policies
3Role of the MPS Aggregate plan: Master production schedule: Specifies the resources available (e.g.: regular workforce, overtime, subcontracting, allowable inventory levels & shortages)Master production schedule:Specifies the number & when to produce each end item (the anticipated build schedule)Disaggregates the aggregate plan
6Objectives of MPS Maintain the desired customer service level Utilize resources efficientlyMaintain desired inventory levels
7Developing an MPS: Assume: Make-to-stock environment Production is in fixed quantities of 125 (MPS)110 units in beginning inventory (BI)
8Sample Problem We start with 110 units in Beginning Inventory Period123456789101112Forecast5075ProjectedAvailableMPSWe start with 110 units in Beginning InventoryProjected Available: How many units are available at the end of each time period?MPS: Replenishment Shipments that need to arrive at the beginning of the time periodProjected Available =BI + MPS - Forecast
9Step 1 Find first negative “projected available” We start with 110 units in Beginning InventoryProjected Available: How many units are available at the endof each time period? (safety stock criteria couldbe in place > 5)MPS: Replenishment Shipments that need to arrive at the beginningof the time period
13Evaluating the MPS Customer service issues: Does “available-to-promise” inventory satisfy customer orders?What new orders can we take from customers and when?
14Available to PromiseWhen a customer places an order, they do not expect immediate delivery (negotiable).The product will delivered by some later date.ATP = how many uncommitted units the company has available at a given time
15New Calculation for Projected Available Period123456789101112Forecast5075Customer Orders35252015ProjectedAvailableAvailable to PromiseMPSProjected Available =BI + MPS – Max (Customer Orders ; Forecast)
16Available-to-Promise “Action Bucket” Period123456789101112Forecast5075Customer Orders35252015ProjectedAvailable6085110Available to PromiseMPS125“Action Bucket” = the current periodOnly calculate ATP during in Action Bucket and when MPS occursATP action bucket = BI +MPS-customer orders before next replenishment– (35+25) = 50
17Available-to-Promise “Replenishment periods” 123456789101112Forecast5075Customer Orders35252015ProjectedAvailable6085110Available to Promise80125115MPSATP for replenishment periodsATP = MPS - customer orders between current MPS and next scheduled replenishmentATP period 3 = 125 – ( )= 80ATP period 5 = 125 – (0 + 15)= 110
18New OrderSuppose we get an order for 200, can we accept this for delivery in period 5?
19Worksheet for New Order for 200 Period123456789101112Forecast5075Customer Orders35252020015ProjectedAvailable6085Available to Promise80MPS125Fit in the order for 200 (can’t change MPS)
20New Order for 200Period123456789101112Forecast5075Customer Orders35252020015ProjectedAvailable6085-40-115-65-15-90Available to Promise80125115MPSNegative number in Projected Available = might be a problem in the futureNegative number in Available to Promise= always a problemSolution?
21Split up New Order for 200 Check to see if this is OK Period 1 2 3 4 5 6789101112Forecast5075Customer Orders45251052011015ProjectedAvailableAvailable to PromiseMPS125Check to see if this is OK
22Can you now take 2 more orders? Period123456789101112Forecast5075Customer Orders4525105201101540ProjectedAvailable6030-20-5-80-30Available to PromiseMPS12550 units to be delivered in Period 830 units to be delivered in Period 12
24Frozen: no changes are possible with a certain period of time (i. e Frozen: no changes are possible with a certain period of time (i.e. 8 weeks)Time Fence (length of period schedule is frozen, liquid, etc.)Demand Fence: MPS numbers do not change and focus is on orders not forecastPlanning Fence: Master Production Scheduler is planning more MPS.
25Rough-cut capacity planning An estimate of the plans’ feasibilityGiven the demonstrated capacity of critical resources (e.g.: direct labor & machine time), have we overloaded the system?