Abstract

The anatomy of a Plant Maintenance Shutdown and Improvement Opportunities

Note: shutdown is  a generic term for what may be called an Outage, Turn Around (TAR) or Overhaul etc.

Running a plant shutdown well has always been key to the financial contribution of a mine. However, something important has changed. The post pandemic reality is that it is harder to retain workers and many of those near retirement just didn’t come back to work. This is creating a shortage of experienced people and a workforce that changes employers easily. We are seeing the impact of this manifested in the erosion of established maintenance and supply chain processes that now struggle to yield the plant runtime that could once be taken for granted. The scope, cost and duration of a shutdown varies widely depending on the nature of the work and the equipment being renewed. The overhaul of an electric shovel might require a week of downtime and cost $100,000. A gold plant may need to go down for 3 days when its time to change mill liners and cost $500,000. In the oil sands, a change of Base of Feed can take months and cost over $1 billion. Despite the huge differences, they all have four common objectives: 1. Do no harm, (safety and environment) 2. Reliability Restoration, i.e., do all the required maintenance to a level of quality that minimizes unplanned shutdowns before the next planned outage, 3 Schedule Compliance, complete the work within the planned shutdown duration or less, 4. Budget Compliance.

Like any other work, executing a shutdown is a process. It can be thought of as a combination of the Weekly Maintenance Work Cycle and a Capex Project as it has elements from both. Any work process can be optimized. Shutdowns have two main loss drivers that impact runtime, those being: shutdown duration, including schedule overruns and unplanned outages post shutdown due to work not completed, or poorly done, during the shutdown  

This paper focuses on how to employ best practices to restore reliability and control schedule compliance as direct drivers of uptime, however it should be noted that the same improvements in execution will also have a positive impact on safety and cost. In this paper, the elements of the shutdown process are broken out sequentially as follows: Planning, Scheduling, Mobilization, Ramp-down, Open – Permits, LOTO on, access, Work Order Execution, Close – Permits, LOTO off Test, Ramp-up,  Demobilization, Post-mortem. Each of these elements are sub-processes that can themselves be optimised. Each element is impacted by the one before it so improvements in each affect the result of the whole.

This paper will explore the process inside each element and identify where the losses can occur. It will suggest mitigation tactics using real examples that have been successfully employed within the industry.