Docstoc

Automated Storage Retrieval System

Document Sample
Automated Storage Retrieval System Powered By Docstoc
					Automated Storage/Retrieval System
    ระบบการจัดเก็บและเบิกจ่ายอัตโนมัติ
Automated Storage/Retrieval
System (AS/RS)
  คือ ระบบที่นางานไปจัดเก็บตามชั้นวางและมีการเบิกจ่ายออกจากชั้นวาง
   อย่างอัตโนมัติ
เหตุผลที่นามาใช้
 To increase storage capacity
   To increase storage density
   To recover factory floor space presently used for
    storing work-in-process (WIP)
   To improve security and reduce pilferage
Automated Storage/Retrieval
System (AS/RS)
เหตุผลที่นามาใช้(ต่อ)
   To reduce labor cost and/or increase labor
    productivity in storage operation
   To improve safety in the storage function
   To improve control over inventories
   To improve stock rotation
   To improve customer service
   To increase throughput
Automated Storage/Retrieval
System (AS/RS)
   Storage structure => Rack system to
    support pallets or shelf system to support
    tote bins
   Motions => Linear motions
   Storage/retrieval operation => travels to
    compartments in rack structure
   Replication of storage capacity
    => Multiple aisles
Unit load AS/RS
        Storage
        structure


                                         Storage
                                         module

S/R machine




                    pickup-and-deposit station
Components and operating
features of an AS/RS
1.   Storage structure
2.   Storage/Retrieval machine
3.   Storage module
4.   One or more pickup-and-deposit station
Application

   AS/RS associated with warehouse and
    distribution operation
   Application AS/RS
     1.   Unit load storage and handling
     2.   Order picking
     3.   work-in-process (WIP) storage system
AS/RS for WIP

 Buffer storage in production
 Support of just-in-time (JIT) delivery
 Kitting of parts for assembly
 Compatible with automatic identification
  systems
 Computer controls and Tracking of
  materials
 Support of factory-wide automation
Engineering analysis of AS/RS
   Sizing the AS/RS rack structure
Engineering analysis of AS/RS
   Sizing the AS/RS rack structure
            Capacity per aisle = 2 ny nz
    ny = number of load compartments along
    the length of the aisle

    nz = number of load compartments that
    make up the height of the aisle
Engineering analysis of AS/RS
   Sizing the AS/RS rack structure
                  number of compartments

                        W = 3(x + a)

                        L = ny (y + b)

                        H = nz (z + c)

x y z = dimension of the unit load

a b c = Allowances design =>

        a = 150 mm b= 200 mm c = 250 mm
EXAMPLE

Four aisles AS/RS is to contain 60 storage
   compartments in length and 12
   compartments vertically and x = 42”
   y = 48” the height of a unit load z = 36”
a) The storage capacity
     capacity per aisle = 2(60) (12)
                         = 1440 unit loads
EXAMPLE

b) The width length and height of the AS/RS
    W = 3(42+6) = 144 in = 12 ft/aisle
Overall width = 4 (12) = 48 ft
    L = 60(48+8) = 3360 in = 280 ft
    H = 12(36+10) = 552 in = 46 ft
Exercise

6- aisle AS/RS , 50 storage compartments in
  the length, 8 compartments in vertical
 unit load x=36” y = 48” z = 30”
กาหนดให้ a = 6” b=8” c=10”
จงหา a)จานวน unit load ทั้งหมด
      b) กว้างx ยาว x สูง
AS/RS Throughput
Methods of AS/RS cycle time to estimate
throughput performance : assumes
1. Randomized storage of loads
2. Storage compartments are of equal size
3. The P&D station is located at the base and
    end of the aisle
4. Constant horizontal and vertical speed of S/R
    machine
5. Simultaneous horizontal and vertical travel
AS/RS Throughput
   The single command cycle time
AS/RS Throughput
  The single command cycle time
Tcs = 2 Max{ 0.5L , 0.5H} + 2 Tpd
               Vy      Vz
    = Max { L , H } + 2 Tpd
            Vy Vz
Tcs = Cycle time of a single command cycle
L = length of the AS/RS H = Height
Vy = velocity along the length
Vz = velocity in the vertical direction
Tpd = Pick/Deposit time
AS/RS Throughput
 •The Dual command cycle time




Tcd = Cycle time of a dual command cycle

Tcd = 2 Max{ 0.75L , 0.75H} + 4 Tpd
              Vy        Vz
      = Max { 1.5L , 1.5H } + 4 Tpd
               Vy     Vz
AS/RS Throughput

  The relative numbers
         Rcs Tcs + Rcd Tcd = 60 U
Rcs = number of single command cycles
   performed per hour
Rcd = number of dual command cycles
   performed per hour
U = system utilization during the hour
AS/RS Throughput

   The total S/R cycle rate (cycles/hr)
               Rc = Rcs + Rcd

   The total number of transactions
    performed per hour
               Rt = Rcs + 2 Rcd
Example 2
             ่
จากตัวอย่างทีแล้ว L = 280 ft H=46 ft
The S/R machine is Horizontal speed = 200 ft/min
Vertical speed = 75 ft/min
P&D operation is 20 sec to accomplish
a) หา Tcs , Tcd
 Tcs = Max{280/200 , 46/75} + 2 (20/60)
    = 2.066 min/cycle
Tcd = Max {1.5x 280/200 ,1.5x 46/75} + 4(20/60)
    = 3.432 min/cycle
Example 2
b) Throughput per aisle ที่ U = 90 % โดยที่ ให้จานวน Single
   command = Dual command
                 Rcs Tcs + Rcd Tcd = 60 U
          Rcs x2.066 + Rcd x3.432 = 60 (0.90)
                   Rcs = Rcd
           5.498 Rcs = 54
                     Rcs = Rcd = 9.822 cycle /hr
                    Rt = Rcs + 2 Rcd
          Rt = 9.822 + 2(9.822) = 29.36 transaction/hr
                                = 29 transaction/hr/aisle
กำหนด 4 aisle    Rt ของ ระบบ   = 4x 29
                                = 116 transaction/hr