Capacity Planning Production Planning and Control
Capacity The throughput, or the number of units a facility can hold, receive, store, or produce in a period of time Determines fixed costs Determines if demand will be satisfied Used to plan overtime horizon
Modify capacity Use capacity Planning Over a Time Horizon Intermediate- range planning SubcontractAdd personnel Add equipmentBuild or use inventory Add shifts Short-range planning Schedule jobs Schedule personnel Allocate machinery * Long-range planning Add facilities Add long lead time equipment *
Design and Effective Capacity Design capacity is the maximum theoretical output of a system Normally expressed as a rate Effective capacity is the capacity a firm expects to achieve given current operating constraints Often lower than design capacity
Utilization and Efficiency Utilization is the percent of design capacity achieved Efficiency is the percent of effective capacity achieved Utilization = Actual Output/Design Capacity Efficiency = Actual Output/Effective Capacity
Bakery Example Actual production last week = 148,000 rolls Effective capacity = 175,000 rolls Design capacity = 1,200 rolls per hour Bakery operates 7 days/week, 8 hours, 3 shifts Design capacity = (7 x 3 x 8) x (1,200) = 201,600 rolls
Bakery Example Actual production last week = 148,000 rolls Effective capacity = 175,000 rolls Design capacity = 1,200 rolls per hour Bakery operates 7 days/week, 8 hours, 3 shifts Design capacity = (7 x 3 x 8) x (1,200) = 201,600 rolls Utilization = 148,000/201,600 = 73.4%
Bakery Example Actual production last week = 148,000 rolls Effective capacity = 175,000 rolls Design capacity = 1,200 rolls per hour Bakery operates 7 days/week, 8 hours, 3 shifts Design capacity = (7 x 3 x 8) x (1,200) = 201,600 rolls Utilization = 148,000/201,600 = 73.4% Efficiency = 148,000/175,000 = 84.6%
Bakery Example Actual production last week = 148,000 rolls Effective capacity = 175,000 rolls Design capacity = 1,200 rolls per hour Bakery operates 7 days/week, 8 hours, 3 shifts Design capacity = (7 x 3 x 8) x (1,200) = 201,600 rolls Utilization = 148,000/201,600 = 73.4% Efficiency = 148,000/175,000 = 84.6%
Bakery Example Actual production last week = 148,000 rolls Effective capacity = 175,000 rolls Design capacity = 1,200 rolls per hour Bakery operates 7 days/week, 8 hours, 3 shifts Efficiency = 84.6% Efficiency of new line = 75% Expected Output = (Effective Capacity)(Efficiency) = (175,000)(.75) = 131,250 rolls
Capacity and Strategy Capacity decisions impact all 10 decisions of operations management as well as other functional areas of the organization Capacity decisions must be integrated into the organization’s mission and strategy
Managing Demand Demand exceeds capacity Limit demand by raising prices, scheduling longer lead time Long term solution is to increase capacity Capacity exceeds demand Stimulate market Product changes Adjusting to seasonal demands Produce products with complimentary demand patterns
Economies and Diseconomies of Scale Economies of scale Diseconomies of scale 25 - Room Roadside Motel 50 - Room Roadside Motel 75 - Room Roadside Motel Number of Rooms Average unit cost (dollars per room per night)
Capacity Considerations Forecast demand accurately Understanding the technology and capacity increments Find the optimal operating level (volume) Build for change
Tactics for Matching Capacity to Demand 1.Making staffing changes 2.Adjusting equipment and processes Purchasing additional machinery Selling or leasing out existing equipment 3.Improving methods to increase throughput 4.Redesigning the product to facilitate more throughput
Complementary Demand Patterns 4,000 4,000 – 3,000 3,000 – 2,000 2,000 – 1,000 1,000 – J F M A M J J A S O N D J F M A M J J A S O N D J Sales in units Time (months) By combining both, the variation is reduced Snowmobile sales Jet ski sales
Approaches to Capacity Expansion (a)Leading demand with incremental expansion Demand Expected demand New capacity (b)Leading demand with one-step expansion Demand New capacity Expected demand (d)Attempts to have an average capacity with incremental expansion Demand New capacity Expected demand (c)Capacity lags demand with incremental expansion Demand New capacity Expected demand
Break-Even Analysis Technique for evaluating process and equipment alternatives Objective is to find the point in dollars and units at which cost equals revenue Requires estimation of fixed costs, variable costs, and revenue
Break-Even Analysis Fixed costs are costs that continue even if no units are produced Depreciation, taxes, debt, mortgage payments Variable costs are costs that vary with the volume of units produced Labor, materials, portion of utilities Contribution is the difference between selling price and variable cost
Break-Even Analysis Costs and revenue are linear functions Generally not the case in the real world We actually know these costs Very difficult to accomplish There is no time value of money Assumptions
Profit corridor Loss corridor Break-Even Analysis Total revenue line Total cost line Variable cost Fixed cost Break-even point Total cost = Total revenue – – – – – – – – – – – |||||||||||| Cost in dollars Volume (units per period)
Break-Even Analysis BEP x =Break-even point in units BEP $ =Break-even point in dollars P=Price per unit (after all discounts) x=Number of units produced TR=Total revenue = Px F=Fixed costs V=Variable costs TC=Total costs = F + Vx TR = TC or Px = F + Vx Break-even point occurs when BEP x = F P - V
Break-Even Analysis BEP x =Break-even point in units BEP $ =Break-even point in dollars P=Price per unit (after all discounts) x=Number of units produced TR=Total revenue = Px F=Fixed costs V=Variable costs TC=Total costs = F + Vx BEP $ = BEP x P = P ==F (P - V)/P F P - V F 1 - V/P Profit= TR - TC = Px - (F + Vx) = Px - F - Vx = (P - V)x - F
Break-Even Example Fixed costs = $10,000 Material = $.75/unit Direct labor = $1.50/unit Selling price = $4.00 per unit BEP $ = = F 1 - (V/P) $10, [( )/(4.00)]
Break-Even Example Fixed costs = $10,000 Material = $.75/unit Direct labor = $1.50/unit Selling price = $4.00 per unit BEP $ = = F 1 - (V/P) $10, [( )/(4.00)] = = $22, $10, BEP x = = = 5,714 F P - V $10, ( )
Break-Even Example 50,000 50,000 – 40,000 40,000 – 30,000 30,000 – 20,000 20,000 – 10,000 10,000 – – |||||| 02,0004,0006,0008,00010,000 Dollars Units Fixed costs Total costs Revenue Break-even point
Break-Even Example BEP $ = F ∑ 1 - x (W i ) ViViPiPiViViPiPi Multiproduct Case whereV= variable cost per unit P= price per unit F= fixed costs W= percent each product is of total dollar sales i= each product
Multiproduct Example Annual Forecasted ItemPriceCostSales Units Sandwich$2.95$1.257,000 Soft drink ,000 Baked potato ,000 Tea ,000 Salad bar ,000 Fixed costs = $3,500 per month
Multiproduct Example Annual Forecasted ItemPriceCostSales Units Sandwich$2.95$1.257,000 Soft drink ,000 Baked potato ,000 Tea ,000 Salad bar ,000 Sandwich$2.95$ $20, Soft drink , Baked , potato Tea , Salad bar , $46, AnnualWeighted SellingVariableForecasted% ofContribution Item (i)Price (P)Cost (V)(V/P)1 - (V/P)Sales $Sales(col 5 x col 7) Fixed costs = $3,500 per month
Multiproduct Example Annual Forecasted ItemPriceCostSales Units Sandwich$2.95$1.257,000 Soft drink ,000 Baked potato ,000 Tea ,000 Salad bar ,000 Fixed costs = $3,500 per month Sandwich$2.95$ $20, Soft drink , Baked , potato Tea , Salad bar , $46, AnnualWeighted SellingVariableForecasted% ofContribution Item (i)Price (P)Cost (V)(V/P)1 - (V/P)Sales $Sales(col 5 x col 7) BEP $ = F ∑ 1 - x (W i ) ViPiViPi = = $67,200 $3,500 x Daily sales = = $ $67, days.446 x $ $2.95 = 32.6 33 sandwiches per day
Decision Trees and Capacity Decision -$14,000 $13,000$18,000 -$90,000 Market unfavorable (.6) Market favorable (.4) $100,000 Large plant Market favorable (.4) Market unfavorable (.6) $60,000 -$10,000 Medium plant Market favorable (.4) Market unfavorable (.6) $40,000 -$5,000 Small plant $0 Do nothing
Strategy-Driven Investment Operations may be responsible for return-on-investment (ROI) Analyzing capacity alternatives should include capital investment, variable cost, cash flows, and net present value
Net Present Value (NPV) whereF= future value P= present value i= interest rate N= number of years P = F (1 + i) N
NPV Using Factors P = = FX F (1 + i) N whereX=a factor from Table S7.1 defined as = 1/(1 + i) N and F = future value Year5%6%7%…10% Portion of Table S7.1
Present Value of an Annuity An annuity is an investment which generates uniform equal payments S = RX whereX=factor from Table S7.2 S=present value of a series of uniform annual receipts R=receipts that are received every year of the life of the investment
Present Value of an Annuity Portion of Table S7.2 Year5%6%7%…10%
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