Witness如何实现拉动式车间仿真

1、订货提前期10个时间单位，每次订购使库存量最大，订货批量为maxstock-storeqty

缺货损失费为每件0.5。库存费为每件0.1。订货固定成本32，变动成本每件3。（单位：元）

2、该系统WITNESS仿真模型界面

3、part元素customer细节设计          

type:active               

input to model.inter arrival:5          

lot size:1          

inputto model.to…:push to ship               

action on create:

batch = ra (1)

ICON = 87"

对buffer元素storehouse细节设计

Capacity:1000

part元素product细节设计

type:active

input to model.inter arrival:1 

lot size:1

PUSH to SERVED

action on create:

ICON = 37 !

storecost = storkqty * 0.1 + storecost

cost = storecost + lostrate + c

对path元素go的设计

Go.Path traverse time:15

Go.Path update interval:0.01

Go.Sourse element:customer

Go.Destination:storehouse

对path元素away的设计

away.Path traverse time:10

away.Path update interval:0.1

away.Sourse element: delivery

away.Destination: ship

对machine元素delivery细节设计

Type:single

Input.from: pull from storehouse

Duration.cycle time:1

Output.to…:push to ship using path

Action on create:

     IF storkqty < batch

            getqty = storkqty

            lostrate = batch - storkqty + lostrate

ELSE

            getqty = batch

ENDIF

Storkqty = storkqty – getqty

对conveyor元素road的设计

Length in parts:10

Index time:1

Input(from…):

   IF storkqty < minstock AND NENTS (road) < 1

           PULL from product out of WORLD

ELSE

           Wait

ENDIF

Action on

Join:

      c = 32 + (maxstock - storkqty) * 3 + c

   front:

       storkqty = maxstock

output(to…):

   PUSH to ship

对initialize action的设计

storkqty = 30

maxstock = 40

minstock = 20