R. Weezenaar MSc


(Deze pagina is alleen beschikbaar in het Engels)

 Maintaining your spare parts in store serviceable.

January 2013

Scientific Supervisor : Drs. J. A. J. P. Donders

Expert Supervisor     : Ir. H. J. Compter

 Different audits within the company E.ON Benelux and articles in reliability magazines have shown that an unknown asset unavailability risk exists as a result of improper or no preservation and/or maintenance on spare parts while they are stored. Some of the parts bought are preserved and come with excellent storage instructions, but not all of them. There are spare parts even without preservation and instructions.

Initiated by the recommendation of the 2009 analysis, an audit on the condition of the spare parts was performed in 2010. In the audit 159 randomly selected spare parts were inspected for technical condition, available label information, storage conditions and preservation. The audit revealed that 42% of the audited items were not in a serviceable condition and these unserviceable equipment’s represented a total value of €220.483,-, which is 50% of the total value of the audited spare parts. The AMC related question that arises is about how to determine the actions for maintaining the serviceable condition of spare parts during their storage period?

The objective of this research is the development of a process to determine the safeguarding actions required to maintain spare parts in a serviceable condition during their storage period by analyzing the different deterioration factors and the different processes to determine maintenance tasks.

First an analysis was provided to determine the deterioration criteria by analyzing the theories of deterioration and preservation. The literature study and internet search revealed that little information with regards to active safeguarding exists. Most of the literature is on the subject of protecting components against the different types of corrosion (passive safeguarding).

The three types of deterioration found in the literature did not provide enough information to accomplish the objective of the research. The definition of deterioration, “The continuous process of getting worse in condition and quality”, gave a good starting point that led to the three changing component characteristics which depict the condition and quality of a component. The changing characteristics led to their inducing factors that can be used in the Safeguard Determination Procedure.

The analysis of the preservation theory provided the substantiation that equipment at the construction site of an asset, installed or not installed, need to be safeguarded until they are commissioned. It also provided a good insight into the difference between passive and active safeguarding.

The research into the process criteria was done by analyzing the current maintenance defining methodologies and by analyzing the procedures of the Original Equipment Manufacturers (OEM’s). This part starts by explaining the connection and reason for serviceable spare parts by looking into the theory of Asset Management Control. The availability of spare parts plays a significant role in the availability of the asset, by shortening the corrective maintenance. The quality of spare parts on stock (available serviceable spare parts) has a direct relation with the asset reliability.

The theoretical analysis of the current maintenance defining methodologies indicated that these methodologies could not be used for the spare parts. The approach is based on the basic of functional failure which does not differentiate between different spare parts. The analysis provided, on the other hand, several ideas, requirements and constraints that can be used in the new Safeguard Determination Procedure.

The research into the procedures of the OEM’s showed that their storage instructions are not determined with a proactive procedure, but are based on experienced functional failures. During the research a commonality in the origin of the OEM instructions was discovered which led to two tables with perishable items that indicate active safeguarding actions.

The development of the Safeguard Determination Procedure is constructed out of the findings of the research into deterioration and the analysis of the maintenance defining methodologies.

The conclusion is that the research objective has been reached with the construction of the Safeguard Determination Procedure based on the two tangible outcomes:

  • a package of safeguarding actions required for maintaining the serviceability of the reviewed spare part;
  • a Net Present Value input for the spare part assessment (METRIC) method with regards to determining the Recommended Spare Parts List.

A less tangible outcome of the procedure is the education on deterioration and safeguarding of the people that are using the Safeguard Determination Procedure.

De Thesis kunt u hier bekijken (EN).

De Thesis presentatie kan hier bekeken worden (EN). 

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