Process Capability Studies Ice Cream Plant

1、Summer 2007 InternshipSchwans Pizza PlantSalina, KSPresentation OutlineBackgroundProjectsAir Leak AuditHand Washing Sink AuditWater Trough AuditStatistical Process ControlReflectionAndrew Sellers Born in Salina B.S. Industrial Engineering at KSU Grad Date: Dec. 2005 Masters Business Admin. at KSU Ex

2、pected Grad. Date: May 2008 Pollution Prevention Institute Intern Career Interests Finance Alternative EnergyEnergy Reduction Projects Air Leak Audit Hand Washing Sink Audit Water Trough Audit Statistical Process Control Analysis of Topping WeightsAir Leak Audit Identified 46 leaks costing Schwans $

3、23,000+ in electricity Common locations: Water Traps Air Hoses Air Hose Nozzles Created maintenance notifications to repair leaks Created Air Leak Audit Procedure for future audits Predictive Maintenance order will come up every 6 months in SAPWater Audit Information Gathered Created map of all sink

4、s in the plant Flow Rates Continuously Running Water Flow Rates - Water Troughs Costs associated with wasted waterWater Project Assumptions Water Cost $1.97 per CCF Natural Gas Cost - $7.00 per DTH Assumed incoming temp was 50oF Assumed boiler operates 60% efficiency WWTP Cost $2.97 per 1000 gallons

5、 Conservative estimate without Fixed Costs Assumed 20% usage of hand washing sinksContinuously Running WaterHand Washing Sink Audit 53 sinks in plant 36 had continuously running water Why? - To keep water at 100oF Average Annual Cost: Water/sink: $373.89 Energy/sink:$788.25 WWTP/sink:$421.66 Average

6、 Total Cost of Continuously Running Water per sink:$1,583.80Alternatives Grundfos Comfort System Installed on sample sink Could not guarantee 100oF Could not overcome any pressure difference Stiebel Eltron Tempra 20 Instantaneous Electric Water Heater Minimum Water Flow is 2.2 GPM Can Handle 60oF Te

7、mperature Rise at 2.2 GPM Cold Water In, 100+oF OutTempra 20 Costs vs. Savings Per Sink Initial Costs$2,500 Unit:$720 Installation:$780 Electrical: $1,000 Annual Savings$654 Water$374 Energy$788 WWTP$422 Electric vs. Gas($930)Instantaneous Water Heater Cash FlowsYear 0Year 1 Year 2 Year 3 Year 4 Yea

8、r 5Initial Investment$-2,500Net Savings$654$654$654$654$654Net Cash Flow$-2,500 $654$654$654$654$654Cost of Capital: 12%Payback Period:3 years 9.9 monthsNPV (5 years only):-143RecommendedWater Trough West EntranceWater Trough Study Performed time study for 30 minutes West Entrance North Trough 59 ga

9、llons were wasted Assume same waste every 30 minutes for 18 hours a day Water Cost:$2,054 Energy Cost:$4,351 WWTP Cost:$2,316 Total Cost:$8,721Recommendations Remove water troughs at West Entrance and replace each with freestanding sinks Superior Plumbing quotes: 4 sinks: $5,800 8 sinks: $11,300 Pay

10、back Period 1 year RecommendedStatistical Process Control Blast 2 Canadian Bacon Veggies Pepperoni Mushroom Sausage Blast 7 Cheese Pepperoni Sauce Blast 3 Line 1 Cheese Line 2 CheeseMethod Collect Data Measure topping weights on all lines 5 Trays at a time Collect 40 samples (Blast 7 20 samples) Ana

11、lyze Data Minitab Control Charts Normality Tests Process CapabilityWhat We Found Machines are not applying toppings evenly Need to balance! Excess Toppings totaling $276,000/year $200,000 from Blast 3 Line 1 Cheese Quality Issues Under applying toppings amounts to $365,000/year Cuts costs, but could

12、 lead to unsatisfied customersBlast 2 - Veggies1-S2-M3-N3.53.02.52.01.51.0DataTarget = 1.9Boxplot of 3-N, 2-M, 1-SBlast 2 Canadian BaconSouth LineMiddle LineNorth Line3.63.43.23.02.82.62.42.2DataTarget = 2.94Boxplot of North Line, Middle Line, South LineBlast 2 - Mushroom1-S2-M3-N3.02.52.01.51.0Data

13、Target = 2.0Boxplot of 3-N, 2-M, 1-S5.14.84.54.23.9LSLTargetUSLLSL4.05Target4.35USL4.65Sample Mean4.42375Sample N40StDev(Within)0.291437StDev(Overall)0.296349Process DataCp0.34CPL0.43CPU0.26Cpk0.26Pp0.34PPL0.42PPU0.25Ppk0.25Cpm0.33Overall CapabilityPotential (Within) Capability% USL27.50% Total35.00

14、Observed Performance% USL21.88% Total31.86Exp. Within Performance% USL22.26% Total32.62Exp. Overall PerformanceWithinOverallProcess Capability of West5.45.25.04.84.64.44.24.0LSLTargetUSLLSL4.05Target4.35USL4.65Sample Mean4.7175Sample N40StDev(Within)0.20714StDev(Overall)0.311578Process DataCp0.48CPL

15、1.07CPU-0.11Cpk-0.11Pp0.32PPL0.71PPU-0.07Ppk-0.07Cpm0.21Overall CapabilityPotential (Within) Capability% USL62.50% Total65.00Observed Performance% USL62.77% Total62.84Exp. Within Performance% USL58.58% Total60.18Exp. Overall PerformanceWithinOverallProcess Capability of EastBlast 3 Line 1 CheeseMean

16、 = TargetMean Target7.26.96.66.36.0LSLTargetUSLLSL6.3923Target6.6923USL6.9923Sample Mean6.70337Sample N40StDev(Within)0.254441StDev(Overall)0.301097Process DataCp0.39CPL0.41CPU0.38Cpk0.38Pp0.33PPL0.34PPU0.32Ppk0.32Cpm0.33Overall CapabilityPotential (Within) Capability% USL17.50% Total37.50Observed P

17、erformance% USL12.81% Total23.88Exp. Within Performance% USL16.86% Total31.94Exp. Overall PerformanceWithinOverallProcess Capability of West7.26.96.66.36.0LSLTargetUSLLSL6.3923Target6.6923USL6.9923Sample Mean6.58975Sample N40StDev(Within)0.222079StDev(Overall)0.257707Process DataCp0.45CPL0.30CPU0.60

18、Cpk0.30Pp0.39PPL0.26PPU0.52Ppk0.26Cpm0.36Overall CapabilityPotential (Within) Capability% USL5.00% Total27.50Observed Performance% USL3.49% Total22.19Exp. Within Performance% USL5.91% Total28.09Exp. Overall PerformanceWithinOverallProcess Capability of EastBlast 3 Line 2 CheeseMean = TargetMean Targ

19、etRecommendations - SPC Continue to collect topping data it is extremely useful in locating sources of waste Standardize measuring trays We noticed a ” difference in diameter of trays being used for the same pizza size Make machine adjustments to balance lines Could save lots of $Summary of Energy Reduction ProjectsProject DescriptionEnvironmental ImpactAnnual CostStatusPlant Air AuditReduce 458,338 kWh of energy/year$23,000In ProgressHandwashing Sink Audit7.5 million gallons/year$77,000Recommend Electric HeatersWater Trough Study4.4 million gallons/year$55,000Recommend Replacing with Ind