**Tid:****21 oktober 1996 kl 1615-1700**

**Plats :****Seminarierummet 3733**, Institutionen för
matematik, KTH, Lindstedts väg 25, plan 7. Karta!

**Föredragshållare:****
Tomas Lund
**

* Titel: *
Beslutsmodeller för försäkringsreservdelar
(Examensarbete)

*
Sammanfattning: *
Expensive components with large production loss costs, due to long
lead times and high production value, but with a very low failure
rate are traditionally called insurance spare parts.

In this thesis a decision ruleing model is developed for aggragate transformers, which are to be considered as insurance spare parts, of the water power plants belonging to Vattenfall.

The model has been implemented in the spreadsheet program Excel for Windows and uses statistical methods for comparing different spare strategies. By calculating and comparing the costs implied using the different spare strategies, the model enables the user to make decisions of optimal strategy and to some extent to consider strategic issues.

By assuming that the number of failures is given by a Poisson distribution the mean yearly costs are obtained from the mean number of failures per year and the production loss costs. Together with the other costs afflicted with the strategy, the strategy comparison cost is obtained by using present value calculating technique.

During the development of the model a study of relevant parameters has been made and to utilize the model optimally an expert overview of these parameters is recommended.

The utilization degree of this model rests heavily on the support and maintenance of the relevant parameters and of the model itself.

A study of the consequences of a joint owner arrangement has also been done.