|dc.description.abstract||The main objective of this master thesis is to develop a generic spare parts evaluation process flow based on NORSOK Z-008 and the daily practice in the Norwegian oil and gas industry. Additionally, a case study has been provided to test the spare parts evaluation process flow developed in the present work.
In logistics, spare parts are an element among various others, such as test and support equipment, transportation, data/documentation and facilities. All these resources need to be fully integrated, as there are many interactions among them. Spare parts can be defined into three categories (including special tools and consumables):
- Commissioning spares.
- Capital spares.
- Operating spares.
Spare parts are required at all times, throughout the lifetime of an asset.
One commonly used formula for calculating the right amount of spare parts is the Poisson formula. The formula uses an expression derived from this distribution. One can also use the economic order quantity (EOQ) equation for determining the size of orders to be placed, when demand is high.
In the oil and gas industry, recommended guidelines such as NORSOK are setting requirements to companies working on the Norwegian continental shelf. For spare parts evaluation, NORSOK Z-008 provides every requirement needed to maintain a safety maintenance program including the spare parts evaluation process.
However, experience has shown that NORSOK Z-008 have been interpreted differently by various companies, and therefore a guideline update with more specific instructions should be considered. By using NORSOK Z-008 (2011) as a background, a new spare parts evaluation process flow has been developed. The process flow consists of four phases; the preparation phase, basic design documentation, spare parts assessment and implementation. These phases have been further developed with sub-processes with the purpose of contributing to a more efficient spare part management with more direct guidelines to use when following the extensive process of spare parts evaluation. The intention has been to make an easy-to-follow, step-by-step process flow, where users own interpretation regarding the process is not necessary.
A case study have been provided, but due to the limited timeframe at disposal for the thesis, some assumptions had to be made. The preparation phase was already performed and given from Det Norske Oljeselskap prior to the case study, together with SPIR forms and other data format preparations. However, the operational spares were tested through most of the sub-processes in the basic design documentation and the spare parts assessment phase with a small range of data from Aker Midsund.
Spare parts evaluation is an extensive process that usually last for two years before the installation goes into operation. Companies have developed individual methods concerning the spare part evaluation, and are usually following the NORSOK recommendations. Developing a generic process that fulfills all the requirements is therefore difficult and comprehensive, yet important in a competitive market as the oil and gas industry is. The NORSOK Z-008 has not been revised since 2011. Due to the industry development the last couple of years, with an increased focus on costs and efficiency, the NORSOK Z-008 (2011) should be considered revised in order to make an easy-to follow, step-by-step process flow, where personal interpretation regarding the process is voided.
The work from this thesis can be continued by developing new methods for evaluating spare parts. Nowadays, several tools have been developed by companies for using in the spare parts evaluation process. Mathematical models used for spare parts evaluation often contains multiple limitations, and therefore new models should be investigated. Other industries should also be considered, such as the Norwegian Armed Forces or the shipbuilding industry.||en