Summarizing our current results with respect to the warehouse design and control problem

1. Summarizing our current results with respect to the warehouse design and control problem Based on: Yoon, C. S. and Sharp, G., “A structured procedure for analysis and design of order pick systems”, IIE Trans., Vol. 28, pgs 379-389, 1996

2. Replenishment Replenishment Reserve Storage and Pallet Picking Case Picking Broken Case Picking Accumulation, Sortation & Packing Direct putaway to reserve Direct putaway to primary Receiving Shipping Cross-docking The warehouse processes and the underlying material flow

3. …or in Yoon and Sharp’s representation... RECEIVING pallets (items totes) cases pallets cases overpacks mul PALLET RESERVE Breakdown function pallets pallets CASE PICK (items cases) pallets cases cases cases ITEM PICK totes (cases) items (items cases) totes SORTING A totes totes Consolidation Function SORTING B (items cases) totes totes cases overpacks UNITIZING totes cases overpacks mul pallets SHIPPING

4. Defining Department and Subsystem structure Department B Department A Transport Equipment 1 Subsystem B1 Subsystem A1 Subsystem A2 Transport Equipment 2 Subsystem B2 Subsystem An Transport Equipment k Subsystem Bn Storage structure (e.g., Gravity Flow Rack) Transport Equipment (e.g., Belt Conveyor) Transport Equipment (e.g., forklift) Transfer Device Storage Equipment Retrieval Equipment (e.g., pick to light) Transfer Device

5. Yoon & Sharp’s design procedure MANAGERIAL CONSIDERATIONS PRODUCT DATA ORDER DATA INPUT STAGE DATA ANALYSIS DATA ANALYSIS SPECIFICATION OF ORDER PICK SYSTEM STRUCTURE SPECIFICATION OF EQUIPMENT SPECIFICATION OP. STRATEGIES SELECTION STAGE MATERIAL FLOW INFORMATION FLOW SUBSYSTEM I SUBSYSTEM II SUBSYSTEM N EVALUATION STAGE SUBSYSTEM RECONCILIATION EVALUATION & SELECTION OVERALL PERFORMANCE ANALYSIS

6. Determining the basic system structure • Product data: • Activity level • requested quantities • product properties • vendor types • Definition of major functional areas / departments • Definition of departmental sub-systems • Storage and material handling modes • Operational policies • storage policies • replenishment policies • order picking policies • batching • sorting • zoning • routing • receiving & shipping policies • Order data: • number of line items • number of items • cubic volume • shipping priorities • product correlation Managerial requirements / company strategy

7. Topics Covered • Equipment types, features and efficiencies • Warehouse Activity Profiling: Product and Order data analysis • Configuration of (departmental) storage: • space allocation • storage sizing • storage mode selection (pallet rack vs. floor storage) and configuration • Optimal sizing and space allocation of the case-pick and item-pick areas; determination of the associated replenishment lots

8. Topics to be addressed next • Warehouse Layout: Spatial Arrangement of the Warehouse departments • Order picking policies: • Routing / sequencing • Batching • Zoning • (Sub-system) Performance Evaluation • Cross-docking

9. Determining the overall Warehouse Layout Based on: E. Frazelle, “World-Class Warehousing”, Logistics Resources International, Inc., 1996 Francis, McGinnis and White, Chpt. 2 and 3

10. Most Typical Warehouse Layouts(according to Frazelle) • U-shaped • Straight-thru • Modular

11. Replenishment Replenishment Reserve Storage and Pallet Picking Case Picking Broken Case Picking Accumulation, Sortation & Packing Direct putaway to reserve Direct putaway to primary Receiving Shipping Cross-docking U-shaped Layout

12. Some key advantages of the U-shaped layout • Excellent utilization of dock resources since the receiving and shipping processes can share dock doors. • Facilitates cross-docking since the receiving and shipping docks are adjacent to each other and may be co-mingled. • Excellent lift-truck utilization since • put-away and retrieval trips are easily combined • storage locations closest to shipping and receiving docks are natural locations to house fast-moving items. => U-shaped layout/flow is the benchmark upon which all other layouts/flows should be compared.

13. Straight-thru Layout(Primarily for cross-docking facilities) SHIPPING SHIPMENT STAGING SORTING AND ASSEMBLY AREA TEMPORARY HOLDING AREA RECEIVING CHECK-IN RECEIVING

14. Modular Layout • Appropriate for large-scale operations in which the individual processes are so large that they merit stand-alone and uniquely designed buildings • E.g., • a rack-supported building for unit-load AS/RS; • an air-conditioned low-bay building for customizing operations such as monogramming, pricing and marking; • a low-bay shipping building equipped with high-speed sortation equipment.

15. Systematic Layout Planning (SLP)(R. Muther, 1961) Input Data and Activities Material Flow Activity Relationships Analysis Relationship Diagram Space Requirements Space Availability Space Relationship Diagram Search Modifying Considerations Practical Limitations Develop Layout Alternatives Selection Evaluation

16. Computerized Layout Generation • Input: Activities, Space Requirements, Material Flows, Adjacency Requirements • Output: A “block” layout • Procedures: • Construction Algorithms: Iteratively, add one more activity to a partial layout until all activities have been placed. • Improvement Algorithms: Starting with a “block” layout, try to improve it, by going through a series of location exchanges for facility pairs or triplets. • Scoring model: An evaluation mechanism that assesses the efficiency of each block layout or insertion step, in the case of construction algorithms, based on the resulting material handling effort or the extent to which the layout satisfies the adjacency requirements expressed in the REL chart. • Example Software: CRAFT, CORELAP, ALDEP, SPIRAL, (AUTOCAD)