ITEM TOOLKIT

Chapter 11 SpareCost 239
CHAPTER 11
SpareCost
SpareCost provides methods for calculating the requirements for replacement of spares for operational systems and
equipment. It generates spare holdings required at Sites (First and second line maintenance by replacement) and at Base
(Third line maintenance to support Sites and repair of returned defective spares). The SpareCost Module supports
algorithms and models defined in Repstock and Optcost provided by British Ministry of Defense.
This chapter:
1. Introduces SpareCost
2. Describes ToolKit’s SpareCost features
3. Outlines an example SpareCost System
4. Describes the SpareCost Editor Screen, Toolbars and Shortcut Keys
1. Introduction
ITEM ToolKit's SpareCost Module calculates the requirements for replacement spares for operational systems and
equipments. It generates spares holding requirements and models the repair of defective items as defined in the Repstock
and Optcost algorithms derived for the British Ministry of Defense. The main driving forces behind the calculations are the
failure rate and cost of replaceable items in a system, together with an acceptable stock out risk. Spares holdings for Sites
(first and second line maintenance by replacement) are calculated using the Optcost method. Base spares requirements
(third line maintenance supporting Sites and repair) are handled by Repstock.
The SpareCost Module makes the following assumptions:
• The system is assumed to be "serial" in nature, i.e. if any one item fails then the whole system ceases to function
and a spare will be required.
• Detection and replacement of items at site is always possible provided a spare is available.
• The time to detect and replace a faulty item is assumed as insignificant.
The SpareCost Module provides:
• Optimization scale of spares at sites for minimum cost.
• Base supported period and repair lead-time.
• Site and Base Stock-Out-Risk.
• Site and Base spare results and cost.