4.7 Production
Figure 4.6 extension the political structure of the production rate (production installments).
Typically the production is involved multiple steps that create meant warehouses to you of jobs in process
(Work in Process or WIP).
Figure 4.6- Production and WIP inventory
WIP is a level increased from the entering flow “production start installments” and diminished from the outgoing flow “production installments”:
- WIP=INTEGRAL (Production Start Installment Installments, WIPt0)
For model variable production the installments uses a delay of third order, delay necessary in order to try physical materials.
The function that, in the software of Powersim study, expresses this delay is DELAYMTR (material delay):
- Production Rate=DELAYMTR (Production Start Installments, Manufacturing Cycle Time, 3)
Manufacturing Cycle Time represents the medium time of transit for all the elements combines to you in the model.
4.8 Production Starts
Figure 4.7 extension the structure of beginning decision production.
In order ability restrictions are not considered now: Production Starts does not depend on the availability of material,
job, or understood them and equipments.
Figure 4.7 - Structure of production Starts
The decisional rules of beginning production are formulated using one generic structure of management of the supplyes.
Production Start Installments is obliged not to be negative but various it equals Desired Production Start Installments
(since still restrictions of resources are not considered).
Desired Production Starts is determined from Desired production installments and Adjustment for WIP (approvigionamento for one
decreasing production):
- Production Start Rate=MAX (0, Desired Production Start installments)
- Desired Production Start Rate=Desired Production+Adjustment for WIP
Adjustment for WIP modification the beginning of the production in order to maintain WIP inventory online with the wished level.
Desired WIP is used in order to supply a level of job in sufficient process to consent the wished rate
given production the current Manufacturing cycle Time:
- Adjustment for WIP= (Desired WIP-WIP Inventory) /WIP Adjustment Time
- Desired WIP=Manufacturing Cycle Time*Desired Production
Desired Production is determined from the rate waited for order (Expected Order Time) modified from Adjustment for Inventory.
Desired Production is obliged not to be negative:
- Desired Production=MAX (0, Expected Order Rate+Adjustment for Inventory)
- Adjustment for Inventory= (Desired Inventory-Inventory/) Inventory Adjustment Time
- Desired Inventory Coverage= Minimum Order Processing Time+Safety Coverage Stock
In order to supply an adequate warehouse like a pad against unexpected variations in question or production, the company tries
to maintain one sure cover of waited for question (Expected Demand).
Desired Inventory Coverage includes two members. First of all, the company must maintain cover to send to
the waited for rate demanding a level base of equal cover to the Minimum Order Processing Time enough (the minimal time in order to work
the order).
According to, in order to assure an adequate level of service the company maintains adds them supply of emergency (Safety
Coverage Stock). Larger it is the cover supplied from the supply of emergency, better will be the level than service.