To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Chapter 12 Enterprise Resource Planning To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved.

Enterprise Resource Planning (ERP) Organizes and manages a company’s business processes by sharing information across functional areas Organizes and manages a company’s business processes by sharing information across functional areas Connects with supply-chain and customer management applications Connects with supply-chain and customer management applications

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. ERP Modules

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. ERP Modules Figure 12.1

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. ERP’s Central Database Finance & Accounting Sales & Marketing Human Resources Production & Materials Management ERP Data Repository Figure 12.2

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. ERP Implementation First step is to analyze business processes First step is to analyze business processes Which processes have the biggest impact on customer relations? Which processes have the biggest impact on customer relations? Which process would benefit the most from integration? Which process would benefit the most from integration? Which processes should be standardized? Which processes should be standardized? Use of Internet portals can aid implementation Use of Internet portals can aid implementation

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Customer Relationship Management (CRM) Plans and executes business processes that involve customer interaction Plans and executes business processes that involve customer interaction Changes focus from managing products to managing customers Changes focus from managing products to managing customers Point-of-sale data is analyzed for patterns used to predict future behavior Point-of-sale data is analyzed for patterns used to predict future behavior

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Supply Chain Management Supply chain planning Supply chain planning Supply chain execution Supply chain execution Supplier relationships Supplier relationships Distinctions between ERP and SCM are becoming increasingly blurred Distinctions between ERP and SCM are becoming increasingly blurred

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Collaborative Product Commerce (CPC) New product design and development and product life cycle management New product design and development and product life cycle management Integrates customers and suppliers in the design process though the entire product life cycle Integrates customers and suppliers in the design process though the entire product life cycle

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Collaborative Product Commerce (CPC) Customer Relationship Management (CRM) Enterprise Resource Planning (ERP) Collaborative Product Commerce (CPC) Supply Chain Management (SCM) Time to Market Time to Customer Customers Product Design Suppliers Collaborative Design Manufacture & Delivery Collaborative Manufacture DFMA Figure 12.3

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Connectivity A very difficult problem A very difficult problem Enterprise Application Integration (EAI) solutions Enterprise Application Integration (EAI) solutions EDI is being replaced by XML EDI is being replaced by XML A continuing issue A continuing issue

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. ERP and MRP MRP (material requirements planning) was the precursor to ERP MRP (material requirements planning) was the precursor to ERP Primarily a production planning and control system Primarily a production planning and control system MRP evolved to MRP II (manufacturing resource planning) MRP evolved to MRP II (manufacturing resource planning) ERP and ERP II continue to extend the links through all business processes ERP and ERP II continue to extend the links through all business processes

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Material Requirements Planning Computerized inventory control & production planning system Computerized inventory control & production planning system Schedules component items when they are needed - no earlier and no later Schedules component items when they are needed - no earlier and no later

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. When to Use MRP Dependent and discrete items Dependent and discrete items Complex products Complex products Job shop production Job shop production Assemble-to-order environments Assemble-to-order environments

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Demand Characteristics Week – – – – No. of tables Continuous demand M T W Th F M T W Th F – – – – No. of tables Discrete demand Independent demand 100 tables Dependent demand 100 x 1 = 100 tabletops 100 x 4 = 400 table legs Figure 12.4

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Material Requirements Planning

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Material Requirements Planning Material requirements planning Planned order releases Work orders Purchase orders Rescheduling notices Item master file Product structure file Master production schedule Figure 12.5

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Master Production Schedule Drives MRP process with a schedule of finished products Drives MRP process with a schedule of finished products Quantities represent production not demand Quantities represent production not demand Quantities may consist of a combination of customer orders & demand forecasts Quantities may consist of a combination of customer orders & demand forecasts Quantities represent what needs to be produced, not what can be produced Quantities represent what needs to be produced, not what can be produced

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Master Production Schedule PERIOD MPS ITEM12345 Clipboard Lapdesk Lapboard Pencil Case

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Product Structure Tree Clipboard Level 0 Level 1 Level 2 Spring (1) Bottom Clip (1) Top Clip (1) Pivot (1) Rivets (2) Clip Ass’y (1) Pressboard (1) Figure 12.6

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Product Structure Tree Top clip (1)Bottom clip (1) Pivot (1)Spring (1) Rivets (2) Finished clipboardPressboard (1) Clipboard Figure 12.6

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Indented Bill of Material Clipboardea Clip Assemblyea Top Clipea Bottom Clipea Pivotea Springea Rivetea Press Boardea1 LEVELITEMUNIT OF MEASUREQUANTITY

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Specialized BOMS Phantom bills Phantom bills Transient subassemblies Transient subassemblies Never stocked Never stocked Immediately consumed in next stage Immediately consumed in next stage K-bills K-bills Group small, loose parts under pseudo-item number Group small, loose parts under pseudo-item number Reduces paperwork Reduces paperwork

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Specialized BOMS Modular bills Modular bills Product assembled from major subassemblies & customer options Product assembled from major subassemblies & customer options Modular bill kept for each major subassembly Modular bill kept for each major subassembly Simplifies forecasting & planning Simplifies forecasting & planning X10 Automobile example X10 Automobile example 3 x 8 x 3 x 8 x 4 = 2,304 configurations 3 x 8 x 3 x 8 x 4 = 2,304 configurations = 26 modular bills = 26 modular bills

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. 4-Cylinder (.40)Bright red (.10)Leather (.20)Grey (.10)Sports coupe (.20) 6-Cylinder (.50)White linen (.10)Tweed (.40)Light blue (.10)Two-door (.20) 8-Cylinder (.10)Sulphur yellow (.10)Plush (.40)Rose (.10)Four-door (.30) Neon orange (.10)Off-white (.20)Station wagon (.30) Metallic blue (.10)Cool green (.10) Emerald green (.10)Black (.20) Jet black (.20)Brown (.10) Champagne (.20)B/W checked (.10) X10 Automobile EnginesExterior colorInteriorInterior colorBody (1 of 3)(1 of 8)(1 of 3)(1 of 8)(1 of 4) Modular Bills of Material Figure 12.7

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Item Master File DESCRIPTIONINVENTORY POLICY ItemPressboardLead time1 Item no.734Annual demand5000 Item typePurchHolding cost1 Product/sales classCompOrdering/setup cost50 Value classBSafety stock 0 Buyer/plannerRSRReorder point39 Vendor/drawing07142EOQ316 Phantom codeNMinimum order qty100 Unit price/cost1.25Maximum order qty500 PeggingYMultiple order qty LLC1Policy code3 Table 12.4

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Item Master File PHYSICAL INVENTORYUSAGE/SALES CODES On hand100YTD usage/sales1100 LocationW142MTD usage/sales75 On order100YTD receipts1200 Allocated75MTD receipts0 Cycle3Last receipt8/25 Last count9/5Last issue10/5 Difference-2 Cost acct Routing00326 Engr07142 Table 12.4

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Basic MRP Processes 1.Exploding the bill of material 2.Netting out inventory 3.Lot sizing 4.Time-phasing requirements

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. The MRP Matrix Gross Requirements Derived from MPS or planned order releases of the parent Scheduled Receipts On order and scheduled to be received Projected on Hand Beg Inv Anticipated quantity on hand at the end of the period Net Requirements Gross requirements net of inventory and scheduled receipts Planned Order Receipts When orders need to be received Planned Order Releases When orders need to be placed to be received on time ITEM NAME OR NO.LLC - LOW LEVEL CODEPERIOD LOT SIZE QTY MADE INLY - LEAD TIME12345 Table 12.5

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Master Production Schedule Clipboard Lapdesk Example 12.1 Item Master File CLIPBOARDLAPDESKPRESSBOARD On hand On order175 (Period 1)00 (sch receipt) (sch receipt) LLC001 Lot sizeL4LMult 50Min 100 Lead time111

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 Product Structure Record Clipboard Lapdesk Pressboard (2) Trim (3’) Beanbag (1) Glue (4 oz) Level 0 Pressboard (1) Clip Ass’y (1) Rivets (2) Level 1

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 ITEM: CLIPBOARDLLC: 0PERIOD LOT SIZE: L4LLT: Gross Requirements Scheduled Receipts175 Projected on Hand25 Net Requirements Planned Order Receipts Planned Order Releases

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 ITEM: CLIPBOARDLLC: 0PERIOD LOT SIZE: L4LLT: Gross Requirements Scheduled Receipts175 Projected on Hand25115 Net Requirements0 Planned Order Receipts Planned Order Releases ( ) = 200 units available ( ) = 115 on hand at the end of Period 1

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 ITEM: CLIPBOARDLLC: 0PERIOD LOT SIZE: L4LLT: Gross Requirements Scheduled Receipts175 Projected on Hand Net Requirements00 Planned Order Receipts Planned Order Releases 115 units available ( ) = 20 on hand at the end of Period 2

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 ITEM: CLIPBOARDLLC: 0PERIOD LOT SIZE: L4LLT: Gross Requirements Scheduled Receipts175 Projected on Hand Net Requirements00100 Planned Order Receipts100 Planned Order Releases units available ( ) = -100 — 100 additional Clipboards are required Order must be placed in Period 2 to be received in Period 3

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 ITEM: CLIPBOARDLLC: 0PERIOD LOT SIZE: L4LLT: Gross Requirements Scheduled Receipts175 Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases Following the same logic Gross Requirements in Periods 4 and 5 develop Net Requirements, Planned Order Receipts, and Planned Order Releases

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 ITEM: LAPDESKLLC: 0PERIOD LOT SIZE: MULT 50LT: Gross Requirements Scheduled Receipts Projected on Hand20 Net Requirements Planned Order Receipts Planned Order Releases

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 ITEM: LAPDESKLLC: 0PERIOD LOT SIZE: MULT 50LT: Gross Requirements Scheduled Receipts Projected on Hand Net Requirements04050 Planned Order Receipts5050 Planned Order Releases5050 Following the same logic, the Lapdesk MRP matrix is completed as shown

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 ITEM: PRESSBOARDLLC: 0PERIOD LOT SIZE: MIN 100LT: Gross Requirements Scheduled Receipts Projected on Hand150 Net Requirements Planned Order Receipts Planned Order Releases ITEM: CLIPBOARDLLC: 0PERIOD LOT SIZE: L4LLT: Planned Order Releases ITEM: LAPDESKLLC: 0PERIOD LOT SIZE: MULT 50LT: Planned Order Releases5050

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 ITEM: PRESSBOARDLLC: 0PERIOD LOT SIZE: MIN 100LT: Gross Requirements Scheduled Receipts Projected on Hand150 Net Requirements Planned Order Receipts Planned Order Releases ITEM: CLIPBOARDLLC: 0PERIOD LOT SIZE: L4LLT: Planned Order Releases ITEM: LAPDESKLLC: 0PERIOD LOT SIZE: MULT 50LT: Planned Order Releases5050 x2 x2 x1 x1 x1

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 ITEM: PRESSBOARDLLC: 0PERIOD LOT SIZE: MIN 100LT: Gross Requirements Scheduled Receipts Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases ITEM: CLIPBOARDLLC: 0PERIOD LOT SIZE: L4LLT: Planned Order Releases ITEM: LAPDESKLLC: 0PERIOD LOT SIZE: MULT 50LT: Planned Order Releases5050

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. School Mate Products Example 12.1 Planned Order Report PERIOD ITEM12345 Clipboard Lapdesk5050 Pressboard

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. MRP Outputs Planned orders Planned orders Work orders Work orders Purchase orders Purchase orders Changes to previous plans or existing schedules Changes to previous plans or existing schedules Action notices Action notices Rescheduling notices Rescheduling notices

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Planned Order Report Table 12.6 Item#2740Date On hand100Lead time2 weeks On order200Lot size200 Allocated50Safety stock50 SCHEDULEDPROJECTED DATEORDER NO.GROSS REQS.RECEIPTSON HANDACTION AL AL GR SR Expedite SR CO GR GR GR Release PO Key:AL= allocatedWO= work order CO= customer orderSR= scheduled receipt PO= purchase orderGR= gross requirement

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. MRP Action Report Table 12.7 Current date ITEMDATEORDER NO.QTY.ACTION # ExpediteSR10-01 # Move forwardPO10-07 # Move forwardPO10-05 # Move backwardPO10-25 # De-expediteSR10-30 # ReleasePO10-13 # ReleaseWO10-24

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Capacity Requirements Planning (CRP) Computerized system that projects load from material plan Computerized system that projects load from material plan Creates load profile Creates load profile Identifies underloads and overloads Identifies underloads and overloads

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Capacity Usually expressed as standard machine hours or labor hours Capacity= (no. machines or workers) x (no. shifts) x (utilization) x (efficiency)

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Capacity Terms Load profile Load profile Compares released and planned orders with work center capacity Compares released and planned orders with work center capacity Capacity Capacity Productive capability; includes utilization and efficiency Productive capability; includes utilization and efficiency Utilization Utilization % of available working time spent working % of available working time spent working

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. More Capacity Terms Efficiency Efficiency Load Load The standard hours of work assigned to a facility The standard hours of work assigned to a facility Load percent Load percent The ratio of load to capacity Load % = (load/capacity)x100% The ratio of load to capacity Load % = (load/capacity)x100%

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Capacity Requirements Planning MRP planned order releases Routing file Capacity requirements planning Open orders file Load profile for each machine center Figure 12.8

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Determining Loads and Capacities 2 copiers, 2 operators 5 days/wk, 8 hr/day 1/2 hr meals, 1/2 hr maintenance per day Efficiency= 100% Utilization= 7/8 = 87.5% Daily capacity= 2 machines x 2 shifts x 8 hours/shift x 100% efficiency x 87.5% utilization = 28 hours or 1,680 minutes Example 12.2

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Determining Loads and Capacities Example 12.2 JOBNO. OFSETUPRUN TIME NO.COPIESTIME (MIN)(MIN/UNIT) TOTAL TIME (500 x 0.08) = , (1,000 x 0.10) = , (5,000 x 0.12) = , (10,000 x 0.14) =1, , (2,000 x 0.10) = min Load percent = 2,385.7 / 1,680 = 1.42 x 100% = 142% Add another shift: Daily capacity= 2 machines x 3 shifts x 8 hours/shift x 100% efficiency x 87.5% utilization = 42 hours or 2,520 minutes Revised load percent = 2,385.7 / 2,520 = x 100% = 94.67%

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Initial Load Profile Figure 12.9 Hours of capacity Time (weeks) Normalcapacity – – – – – – – – – – – – 0 0 –

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Remedies for Underloads 1.Acquire more work 2.Pull work ahead that is scheduled for later time periods 3.Reduce normal capacity

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Remedies for Overloads 1.Eliminate unnecessary requirements 2.Reroute jobs to alternative machines or work centers 3.Split lots between two or more machines 4.Increase normal capacity 5.Subcontract 6.Increase the efficiency of the operation 7.Push work back to later time periods 8.Revise master schedule

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Adjusted Load Profile Figure Hours of capacity Time (weeks) Normalcapacity – – – – – – – – – – – – 0 0 – Pull ahead Push back Overtime Work an extra shift

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Relaxing MRP Assumptions Material is not always the constraining resource Material is not always the constraining resource Lead times can vary Lead times can vary Not every transaction needs to be recorded Not every transaction needs to be recorded JIT can be used with MRP JIT can be used with MRP The shop floor may require a more sophisticated scheduling system The shop floor may require a more sophisticated scheduling system

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Manufacturing Resource Planning (MRP II)

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Manufacturing Resource Planning (MRP II) Forecast Aggregate production plan Customer orders Feasible? Master production schedule Material requirements planning Capacity requirements planning Feasible? Purchase orders Work orders Inventory Shop floor control Manufacture No Yes Feedback No Yes Figure 12.11

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Manufacturing Resource Planning (MRP II) Forecast Aggregate production plan Customer orders Feasible? Master production schedule Material requirements planning Capacity requirements planning Feasible? Purchase orders Work orders Inventory Shop floor control Manufacture No Yes Feedback No Yes Figure Forecast Aggregate production plan Customer orders Feasible? Master production schedule No Yes

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Manufacturing Resource Planning (MRP II) Forecast Aggregate production plan Customer orders Feasible? Master production schedule Material requirements planning Capacity requirements planning Feasible? Purchase orders Work orders Inventory Shop floor control Manufacture No Yes Feedback No Yes Figure Master production schedule Material requirements planning Capacity requirements planning Feasible? Yes No

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Forecast Aggregate production plan Customer orders Feasible? Master production schedule Material requirements planning Capacity requirements planning Feasible? Purchase orders Work orders Inventory Shop floor control Manufacture No Yes Feedback No Yes Manufacturing Resource Planning (MRP II) Figure Inventory Shop floor control Manufacture Purchase orders Work orders

To Accompany Russell and Taylor, Operations Management, 4th Edition,  2003 Prentice-Hall, Inc. All rights reserved. Manufacturing Resource Planning (MRP II) Forecast Aggregate production plan Customer orders Feasible? Master production schedule Material requirements planning Capacity requirements planning Feasible? Purchase orders Work orders Inventory Shop floor control Manufacture No Yes Feedback No Yes Figure 12.11