Plan for the “What-Ifs” – A Tubular Example

Introduction

Anyone who has experience in planning or working turnarounds understands that, as a rule of thumb, the cost of any given task tends to increase by about five times when compared to routine maintenance and inspection. This can be attributed to numerous factors, including increased labor rates and overtime, increased demand for tools and equipment, bottlenecks due to delays for various reasons, turnaround scope creep, and lost opportunity costs of production.

Furthermore, turnarounds require a tremendous amount of planning and coordination, the lack of which can lead to costly delays and frustration for those involved. This planning should take into consideration all of the “what-ifs” that may arise during the project, as well as the proper course of action to take if and when a “what-if” does occur. Each of these “what-ifs” require a decision to be made, decisions take time and time equates to money.

This article describes the application of decision trees (also referred to as workflows) to help inspectors and technicians make decisions related to common turnaround processes. Decision trees are graphical representations of conditions, tasks, and outcomes that can be applied to nearly any closed loop mechanical integrity or inspection workflow process. They can be used to spell out the tasks involved in a process, or to connect multiple processes together in a logical manner.
As a practical example of the concept and application of decision trees, this article focuses on how decision trees can be applied to heat exchanger tubular inspection. However, one should consider the numerous other activities that can be made more efficient and streamlined by using decision trees. For example:

• Holistic mechanical integrity implementation processes
• Inspection, testing, and preventive maintenance workflows
• Turnaround inspection planning workflows
• Engineering similar service studies and damage mechanism assessments
• Higher-level process safety management processes