• No results found

Determination of Batch-Sizes  A case-study in the process industry

N/A
N/A
Protected

Academic year: 2021

Share "Determination of Batch-Sizes  A case-study in the process industry"

Copied!
1
0
0

Loading.... (view fulltext now)

Full text

(1)

Determination of Batch-Sizes

A case-study in the process industry

Viktor Farbäck & Simon Gottfridsson Lund University, Faculty of Engineering (LTH)

Picture the scenario; you work at a company which produce around 400 types of drinks, in various bottles and selling units. Your responsibility is to plan which beverage to be produced. Today’s assignment is to plan the production sequence for 10 different kinds of beers. How should this be done in a cost-efficient way?

You know approximately, but not exactly, how much of these beers that are demanded every week. Every time you want to change the kind of beer the machines are producing, there is a cost

associated to it. For each day you store the beer that you have produced but not yet sold, there is also a cost. Add to this scenario that the products have an expiry date which is different for each beverage. Products that not are sold by this date, must be thrown away. The question now becomes, how much of each beer should you produce every time you have the machine set up for a product? You don’t want to produce each type too often, because of the cost when changing products. But you don’t want to produce it too seldom either, as the amount you must carry in stock each day is costly, and there is a risk that you produce goods that perish.

But what if the buyer wants to buy more than expected of a certain beer? What if the yield from the production does not meet the expectations? There need to some sort of mechanism in place to protect us from these uncertainties, to minimize the risk that we cannot satisfy the customer demand from our stock.

During our thesis, we have developed a quantitative model that will help the planner to make these decisions. The model will not only tell you how much of each beer to make every time, in a more cost-efficient way, the suggestion is also based on operational constraints and the risk for products to perish.

Since you don’t know exactly how much beer the customer will buy, the model also helps you to decide how much safety stock you will need, in case the quantity is not enough until the next

production time. The model contains a way of calculating this safety stock that incorporates both the variations in yield and customer demand, while also recognizing the reductions in risk that a greater batch size provides.

When we have tested the created model, we have been able to generally increase the batch sizes, thus increasing the performance of the production facility. Since our new way of calculating safety stock incorporates the positives of greater batch sizes, the result doesn’t drastically increase the average stock levels.

References

Related documents

För att uppskatta den totala effekten av reformerna måste dock hänsyn tas till såväl samt- liga priseffekter som sammansättningseffekter, till följd av ökad försäljningsandel

Från den teoretiska modellen vet vi att när det finns två budgivare på marknaden, och marknadsandelen för månadens vara ökar, så leder detta till lägre

The increasing availability of data and attention to services has increased the understanding of the contribution of services to innovation and productivity in

Av tabellen framgår att det behövs utförlig information om de projekt som genomförs vid instituten. Då Tillväxtanalys ska föreslå en metod som kan visa hur institutens verksamhet

Generella styrmedel kan ha varit mindre verksamma än man har trott De generella styrmedlen, till skillnad från de specifika styrmedlen, har kommit att användas i större

Parallellmarknader innebär dock inte en drivkraft för en grön omställning Ökad andel direktförsäljning räddar många lokala producenter och kan tyckas utgöra en drivkraft

Närmare 90 procent av de statliga medlen (intäkter och utgifter) för näringslivets klimatomställning går till generella styrmedel, det vill säga styrmedel som påverkar

I dag uppgår denna del av befolkningen till knappt 4 200 personer och år 2030 beräknas det finnas drygt 4 800 personer i Gällivare kommun som är 65 år eller äldre i