- Problem Definition
Reliability of equipment in oil and gas industry has been main concern in our company, storage tank to be specific. As main equipment it needs special attention, since we are taking care hydrocarbon product, which is highly flammable. Our goals are to assess reliability of storage tank such as corrosion rate and remaining plate thickness. To achieve our goals, it is important to determine the most economical method to asses reliability or conduct inspection of storage tank.
- Development of feasible alternatives
To asses corrosion rate and remaining plate thickness alternatives :
- Investing an Ultrasonic Thickness (UT) Crawler as inspection tools
- Hire third party specialize on storage tank inspection
It is important to choose which most efficient way to conduct inspection, especially with numerous number of storage tank.
- Possible Solution / Alternative
Calculation of investment, maintenance cost, operating cost and rent cost based on inquiry from UT Crawler Vendor and Third Party specialize in this field.
- Selection of Criteria
Summary result of investing and renting data :
Table 1: Investing vs Renting from Third Party
As shown on the table 1, if we rent from 3rd party company we dont have to deal with maintenance cost, while if we purchase we must consider maintenance cost, operating cost beside investment cost.
- Analysis and Comparison of the Alternatives
Total number of inspection based on our work plan and KPI. In 1 month we must performed at least 2 storage tank inspection, therefore in 1 year we have target at least 24 storage tank to be inspected. We assume that our equipment have 5 years life expectancy. This will be our baseline for calculation.
Table 2: Useful life and Total Number of Inspection in 1 year
Calculation summary :
Table 3 : Summary total cost inspection 24 storage tank/year for 5 years inspection
- Selection and Preferred Alternatives
Table 3 show that total cost of invest UT Crawler is lower thant rent from 3rd party. The biggest difference in operational cost, this cost reduction more than balance the extra $53.383 in investment. In short run, one year or less, we can consider outsourced inspection activity. But for this case, long term inspection with numerous number of tank, investment on UT crawler will be economically feasible.
- Performance Monitoring and the Post Evaluation of Result
Periodic monitoring and maintenance is needed to conduct, for company to make sure equipment in the best condition. Review shall be conducted to reveal uncertainty parameter such as overhead and cost of run.
- Sullivan, William G., Wicks, Elin M. & Koelling, C. Patrick. (2014). Engineering Economy 16th edition page 71-73, England: Pearson Education Limited.
- W2_AL_Sleeping Field Development (2013, March).
Retrieved from https://kristalaace2014.wordpress.com/2014/03/03/w2_al_sleeping-field-development/#more-269
- W02.1_SJP_Bamboo Scaffolding ((2017, June)
Retrieved from https://js-pag-cert-2017.com/w02-1_sjp_bamboo-scaffolding/