Supermarket Operation Process Flowchart by dsc89947

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        Receiving and Shipping                                         Receiving and Shipping

• Consider handling, storing, and control                           Facility Requirements
  requirements to provide the proper                                • Receiving
  combination of space, equipment, and                                  – Stage and spot carriers
  people.                                                                     » Waiting
                                                                              » Maneuvering
                                                                              » Unloading
• Receiving and shipping functions interface                            –   Dockboards
  with the outside environment.                                         –   Receiving area
                                                                        –   Staging area
                                                                        –   Office area
                                                                    • Shipping
                                                                        –   Staging area (may include accumulate and pack)
                                                                        –   Office area
                                                                        –   Stage and spot carriers
                                                                        –   Dockboards
                                                  INEN 416                                                              INEN 416




                                                             3                                                                     4



        Receiving and Shipping                                         Receiving and Shipping

• Desirable Attributes                                           • Other Considerations
   – Directed flow paths (watch out for double handling)            – Smooth interface between vendor's and receiver's
   – Continuous flow of effort (try to schedule inbound               (or shipper's and customer's) information system
     shipments)                                                     – Returnable containers (including attrition and
   – Concentrated area that minimizes material handling               replacement)
   – Efficient material handling (try to influence unit             – Returned goods
     load configuration)                                            – Returning carriers, i.e., backhaul (maximize
   – Providing safe operations                                        utilization of shipper owned carriers)
   – Minimizing damage                                           • Coordination of Receiving and Shipping
   – Providing good housekeeping                                    – Common space, equipment, and/or personnel might
                                                                      be used
                                                                    – Return of slave pallets for manufacturing
                                                                    – Possible centralization of the functions (i.e.,
                                                                      receive in the morning and ship in the afternoon)
                                                  INEN 416                                                              INEN 416




                                                             5                                                                     6


        Receiving and Shipping                                         Receiving and Shipping
             Arrangement
  Highway or Railroad
                                                                 Space Planning
    R            S      R       S     R   S

                                                                 • What is to be receiving and shipped?

                                                                 • Number and type of docks
    R            S          R   S     R


                                                                 • Space requirements for receiving and
                                                  S                shipping area

    R                   R                     R                  Receiving and Shipping Analysis Chart

    S                           S             S




                                                  INEN 416                                                              INEN 416
                                                                                         7                                                                  8



                   Receiving and Shipping                                                             Receiving and Shipping

      Docks                                                                                   Internal Area Requirements
      • Number                                                                                • Space Allocations For
             – Estimate with                                                                     –   Personnel convenience
                   » Queueing analysis                                                           –   Offices
                   » Simulation                                                                  –   Material handling equipment maintenance
      • Configuration                                                                            –   Trash disposal
             –   Carrier approaches                                                              –   Pallet and packaging material storage
             –   Carrier traffic flow                                                            –   Trucker's lounge
             –   Carrier waiting area                                                            –   Buffer or staging area
             –
             –
                 Apron Depth
                 Bay Width          }
                                    90 degree versus finger docks
                                                                                                 –   Material handling equipment maneuvering




                                                                           INEN 416                                                              INEN 416




                                                                                         9                                                                  10



                   Receiving and Shipping                                                                  Equipment Planning

      • Area Requirement Example                                                              • Equipment required for a proper interface
                                                                 Dock Face                      between the carriers and the docks.
                        Truck Waiting   24'                                        6'            – Dock levelers
                 123'                                           Maneuvering        12'                »   Portable ramp
12'                                                   12'
                                                                                                      »   Permanent ramp
                                                                                   26'                »   Yard ramp
                                                                                                      »   Scissor lift
                           Plant                                                                 – Bumper pads
                                                                                   26'
                                                                                                 – Dock shelters

      Exit                                    Enter         10' 7' 10' 7' 10' 8'




                                                                           INEN 416                                                              INEN 416




                                                                                         11                                                                 12



                   Receiving and Shipping                                                            Storage and Warehousing

      • Conclusion                                                                            • Storage Function
             – Receiving and shipping are important, but often                                   – Activity of storing raw materials, supplies, and in
               overlooked, functions.                                                              process material.
             – They deserve the same systematic planning                                      • Warehousing Function
               procedure that is afforded the rest of the
               manufacturing process.                                                            – Activity of storing finished goods.




                                                                           INEN 416                                                              INEN 416
                                                                                                                             13                                                                           14



       Storage and Warehousing                                                                                                             Storage and Warehousing

• Basic Functions                                                                                                                 • Goal:
   –   Receiving
                                                                                                                                     – Maximize resource utilization while satisfying customer
   –   Identification and sorting                                                                                                      requirements, or
   –   Dispatching to storage
                                                                                                                                     – Maximize customer service subject to resource constraints
   –   Placing in storage
   –   Storage                                                                                                                    • Resources:
   –   Removing from storage                                                                                                         – Space
   –   Order accumulation                                                                                                            – Equipment
   –   Packing                                                                                                                       – Personnel
   –   Shipping
   –   Record keeping
                                                                                                                                  • Objectives:
                                                                                                                                     –   Maximize space utilization
• Additional Functions                                                                                                               –   Maximize equipment utilization
   –   Inbound inspection
                                                                                                                                     –   Maximize labor utilization
   –   Parts preparation
                                                                                                                                     –   Maximize accessibility of all materials
   –   Kitting
   –   Item packaging                                                                                                                –   Maximize protection of all materials
                                                                                                                  INEN 416                                                                  INEN 416




                                                                                                                             15                                                                           16



       Storage and Warehousing                                                                                                             Storage Location Methods

SPACE PLANNING                                                                                                                      • Randomized Storage
         Storage Analysis Chart                                                                                                          – An individual stock keeping unit (SKU) can be
                                                                                                                                           stored in any available storage location.
                                                                                                                                         – An inbound load is assigned to the closest
                                                                                                                                           available storage location.
                                                                                                                                         – Retrievals are first-in, first-out (FIFO).
                                                                                                                                    • Dedicated Storage
                                                                                                                                         – Each SKU is assigned to a specific storage location
                                                                                                                                           or set of locations.
                                                                                                                                         – Storage locations can be arbitrarily determined,
                                                                                                                                           such as part number sequence, or they can be
                                                                                                                                           determined based on the SKU's activity level and
                                                                                                                                           inventory level.
                                                                                                                                         – Number of storage locations is the sum of the
                                                                                                                                           maximum inventory level for each SKU.
                                                                                                                  INEN 416                                                                  INEN 416




                                                                                                                             17                                                                           18



       Storage Location Methods                                                                                                            Storage Location Methods

• Example                                                                                                                         • Dedicated Storage
            P e r io d            1           2
                                                         P ro d u c ts
                                                          3           4        5      6        A g g r e g a te                     – Maximize Throughput
                1                24          12           2        12         11     12              73
                2
                3
                                 22
                                 20
                                              9
                                              6
                                                          8
                                                          6
                                                                      8
                                                                      4
                                                                              10
                                                                               9
                                                                                      9
                                                                                      6
                                                                                                     66
                                                                                                     51
                                                                                                                                          » Assign SKUs to storage locations based on the ratio of
                4                18           3           4        24          8      3              60                                     their activity to the number of locations assigned to the
                5
                6
                                 16
                                 14
                                             36
                                             33
                                                          2
                                                          8
                                                                   20
                                                                   16
                                                                               7
                                                                               6
                                                                                     24
                                                                                     21
                                                                                                    105
                                                                                                     98                                     SKU. (NOTE: Activity is the number of storages/retrievals
                7
                8
                                 12
                                 10
                                             30
                                             27
                                                          6
                                                          4
                                                                   12
                                                                      8
                                                                               5
                                                                               4
                                                                                     18
                                                                                     15
                                                                                                     83
                                                                                                     68
                                                                                                                                            per unit time not the quantity of material moved.)
                9                 8          24           2           4        3     12              53
               10                 6          21           8        24          2      9              70                                   » SKU with the highest ranking is assigned to the preferred
               11
               12
                                  4
                                  2
                                             18
                                             15
                                                          6
                                                          4
                                                                   20
                                                                   16
                                                                               1
                                                                              24
                                                                                      6
                                                                                      3
                                                                                                     55
                                                                                                     64                                     openings (i.e., closest to the I/O point).
               13                24          12           2        12         23     24              97
               14
               15
                                 22
                                 20
                                              9
                                              6
                                                          8
                                                          6
                                                                      8
                                                                      4
                                                                              22
                                                                              21
                                                                                     21
                                                                                     18
                                                                                                     90
                                                                                                     75                           • Class Based Storage
               16                18           3           4        24         20     15              84
               17
               18
                                 16
                                 14
                                             36
                                             33
                                                          2
                                                          8
                                                                   20
                                                                   16
                                                                              19
                                                                              18
                                                                                     12
                                                                                      9
                                                                                                    105
                                                                                                     98
                                                                                                                                          » Hybrid configuration which assigns SKUs to classes based
               19                12          30           6        12         17      6              83                                     on their activity-to-space ratios, but uses randomized
               20                10          27           4           8       16      3              68
               21                 8          24           2           4       15     24              77                                     storage within the classes.
               22                 6          21           8        24         14     21              94
               23
               24
                                  4
                                  2
                                             18
                                             15
                                                          6
                                                          4
                                                                   20
                                                                   16
                                                                              13
                                                                              12
                                                                                     18
                                                                                     15
                                                                                                     79
                                                                                                     64
                                                                                                                                          » Yields some of the throughput benefits of dedicated storage
                                                                                                                                            and the space benefits of randomized storage.
            M a x im u m o f a g g r e g a t e in v e n t o r y le v e l =          1 0 5 p a lle t lo a d s

                                                                                                                                  • Supermarket Storage
            S u m o f in d iv id u a l m a x im u m in v e n t o r y le v e ls =    140
            A v e r a g e in v e n t o r y le v e l =                              7 7 .5
            M in im u m o f a g g r e g a t e in v e n t o r y le v e l =             51

                                                                                                                                          » Combination of random and assigned storage.
                                                                                                                  INEN 416                                                                  INEN 416
                                                                                                      19                                                                        20



            Storage and Warehousing                                                                                Storage and Warehousing

     • Loss of Cube Utilization                                                                             • Loss of Cube Utilization
         – Aisle Example                                                                                       – Honeycombing
                     18' Clear Stack Height
                                                                                                                    » Wasted space that results because a partial row or
                      4'
                                      9'
                                                     4'                                                               stack cannot be utilized because adding materials
                                                                                                                      would result in blocked storage.
                                                                                                                             Ceiling                       Aisle


                                                                                                                            A                          A
                                                            36'
                                                                                                                            A                          A
                             10'             10'                                                                            A     A                    A       A
                                                                                                                             Floor                   Outside wall
                    10'         Main Aisle
                                                                                                            • Space Standard
                          Total Cube = 30,636 cubic feet                                                       – Volume requirement per unit load stored to include
                          Aisle Cube = 19,620 cubic feet
                                                                                                                 allocated space for aisles and honeycombing.
                          Percentage of total volume allocated to aisles = 64%

                                                                                        INEN 416                                                                    INEN 416




                                                                                                      21                                                                        22



            Storage and Warehousing                                                                                Storage and Warehousing

     Equipment Planning                                                                                     Layout Planning
     • Storage Equipment Types                                                                              • Objectives
         – Bulk Storage -- includes block and tight-blocking                                                   – To utilize space effectively
           stacking                                                                                            – To provide efficient materials handling
         – Portable Racks or Stackable Racks                                                                   – To minimize storage cost while providing the
         – Pallet Rack                                                                                           required levels of service
         – Cantilever Racks -- provide long uninterrupted                                                      – To provide maximum flexibility
           spans                                                                                               – To provide good housekeeping
         – Drive-In or Drive-Through Racks
                                                                                                            • Principles
         – Flow-Through Rack
                                                                                                               –   Popularity
         – Bin Racks or Shelving                                                                               –   Similarity
         – Sliding Racks                                                                                       –   Size
                                                                                                               –   Characteristics
                                                                                                               –   Space Utilization
                                                                                        INEN 416                                                                    INEN 416




                                                                                                      23                                                                        24



            Storage and Warehousing                                                                                Storage and Warehousing

     • Popularity                                                                                           • Layout Principles
                                                                                    Average
                                                   Quantity per       Trips to      Customer     Trips to
                                                                                                               – Similarity
                                   Product            Receipt         Receive      Order Size     Ship              » Items that are received and shipped together should
                                      A              40 pallets          40         1.0 pallet      40                be stored together.
                                      B             100 pallets         100        0.4 pallets     250
 Slow                                                                                                          – Size
                                      C             800 cartons         200        2.0 cartons     400
Moving
                                      D              30 pallets          30        0.7 pallets      43
                                                                                                                    » Provide a variety of storage location sizes to
                                      E              10 pallets          10        0.1 pallets     100
                                      F             200 cartons          67        3.0 cartons      67
                                                                                                                      accommodate a variety of products.
    Medium Fast Entrance
    Moving Moving and Exit            G            1000 cartons         250        8.0 cartons     125              » Utilize adjustable racks or shelves if product and unit
                                      H            1000 cartons         250        4.0 cartons     250                load sizes are uncertain or change periodically.
                                                                                                               – Characteristics
                                                                  H     F    D     B                                »   Perishable materials
                                                                                                                    »   Oddly shaped items
                                                       Receive        Main Aisle       Ship                         »   Crushable items
                                                                                                                    »   Hazardous materials
                                                                  G     A    C     E                                »   Security of items from pilferage
                                                                                                                    »   Compatibility between items
                                                                                        INEN 416                                                                    INEN 416
                                                                         25                                                                       26



                   Space Utilization                                                 Warehouse Layout Models

• Conservation of Space                                                       • Determine the optimal dedicated storage layout
   – Maximizing concentration                                                 • Notation
   – Maximizing cube utilization                                                 – q = number of storage locations
   – Minimizing honeycombing                                                     – n = number of products
                                                                                 – m = number of I/O points
• Limitations of Space
                                                                                 – Sj = number of storage locations required for product j
   –   Clear height
                                                                                 – Tj = number of trips in/out of storage for product j
   –   Stacking height                                                             (throughput)
   –   Floor loading                                                             – pij = percentage of travel through I/O point i for product j
   –   Columns                                                                   – dik = distance (or time) required to travel from I/O point i
• Materials Accessibility                                                          to storage location k
   –   Each storage face has aisle access                                        – xjk = 1 if product j is assigned to storage location k; = 0,
                                                                                   otherwise
   –   Majority of items stored along the long axis of the area
   –   Aisles should not be placed along walls without doors
   –   Avoid locked stock by using a two-bin system
                                                              INEN 416                                                                 INEN 416




                                                                         27                                                                       28



  Warehouse Layout Formulation                                                Warehouse Layout Formulation

                                                                              • fjk = expected distance traveled between storage
                         n q m       Tj
                 Min ∑ ∑ ∑                  pij d ik x jk                       location k and the docks for product j
                         j =1k =1i =1 S j                                                m
                                                                                  f jk = ∑ pij d ik
                 st :                                                                    i =1
                         n                                                              n q     Tj               n q
                                                                                  Min ∑ ∑            f jk x jk = ∑ ∑ c jk x jk
                        ∑ x jk = 1              k = 1,L, q
                                                                                       j =1k =1S j               j =1k =1
                        j =1
                         q
                                                                                                     Tj
                                                                                  where c jk =            f jk
                        ∑ x jk = S j             j = 1,L, n                                          Sj
                        k =1                                                  • Rewritten in this form, this problem looks like a
                        x jk ∈ {0,1} ∀j , k                                     transportation problem
                                                                                 – Can use any standard procedure to solve or specialized
                                                                                   algorithms like WHAP

                                                              INEN 416                                                                 INEN 416




                                                                         29                                                                       30



   Warehouse Layout Algorithm                                                    Warehouse Layout Example

 • If probabilities of using the I/O points are
   independent of the product types, that is
       – pi = pij for all j
 • Then we can use the following algorithm to
   minimize the total distance travelled
       – Number the products in non-increasing order of
         their Tj/Sj values
            T1 T2     T
              ≥    ≥L≥ n
            S1 S 2    Sn
       – Compute the fk value for each storage location
       – Assign product 1 to the S1 storage locations having
         the lowest fk values; assign product 2 to the S2
         locations having the next lowest fk values; …


                                                              INEN 416                                                                 INEN 416
                                                           31



               Storage Models

• Determine best design for each storage
  subsystem
• Unit loads stored and retrieved with lift trucks
• Four conventional storage methods analyzed
   –   Block stacking
   –   Deep lane storage
   –   Single-deep rack
   –   Double-deep rack
• Tradeoff between density of storage and
  accessibility
   – Have different types of space losses due to rack
     design and honeycombing
   – Minimize average amount of floor space required


                                                INEN 416

								
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