Unplanned downtime reduction     Back to Services

Stabilising your operation by systematically eliminating the repeat offenders

Introduction

Transforming reactive maintenance departments into proactive ones requires a structured approach focusing on short-term gains and long term sustainability. While this approach will differ by site and needs to be determined by a site review, on most reactive sites it will make sense for one of the first initiatives to focus on eliminating the largest repeat failures.

By tackling repeat offenders as a first step, you generate fast financial results and reduce production disruptions. This provides a morale boost to the maintenance team and frees employees to improve the business rather than fire fight, winning the necessary support to continue improving maintenance and initiate other important but slower changes.

While the approach would differ depending on the site’s specific needs, five basic steps are outlined below as are some examples of the results that this can achieve. These are typically carried out along with work on Planned Shuts, Workshop efficiency and effectiveness, and installing preventative maintenance tools and techniques. These as are covered in the maintenance section of Our Services on the website as well.

Our Approach

Step 1 - Pareto – Main causes of downtime at a selected client

Step 2 - Value Ease Matrix is used to prioritise the maintenance causes that will be tackled

Step 3 & 4 – Failure causes are identified and ideas to eliminate these are generated in structured idea generation sessions

Step 5 - Our approach explicitly manages the whole Ideas Pipeline… and is continuous

Some results from tackling unplanned downtime are illustrated by the following cases:

Underground hard rock zinc mine: Nearly all underground mines incorporate some form of de-watering system composed of sumps, drains and pumps to manage excess water. Flooding caused by premature pump failure or blockages can result in flooding of a level or those below, causing them to be evacuated and stopping mining activities such as development, production drilling and stope mucking.

At this site, the top item on the unplanned downtime pareto for lost production was pump failures, and within this, the main root cause was preventable contamination of the pumps. The main causes within this were:

• Lack of understanding of the role of contamination on equipment failures
• Lack of any preventative system for ensuring that all pumps and sumps were checked and cleaned regularly
• Lack of accountability (it was simply given to any one who needed a job)

The team identified several preventative actions to decrease premature pump failures and flooding caused by contamination:

• Carry out extensive communication and training on contamination and its impact on failures
• Implement and sustain pump cleaning and sump bogging schedules
• Install steel mesh screens on mono pumps to prevent ingress of large particles
• Install drums to permanently remove fibers and rubbish from the underground
• Develop new design of sumps to prevent ingress
• Install mesh filters on submersible pumps
• Ensure elbows are installed on all pumps to prevent ingress

These actions, combined with establishing clear accountabilities for preventative inspections and for pump maintenance resulted in a 70% decrease in lost production due to level flooding.

Electrical Motors: At a major site, hundreds of electrical motors of various sizes were employed. Although individually generally of small value, these motors’ unplanned downtime was identified by pareto analysis to represent the highest repair cost in the facility.

The PIP and client team decided to tackle this issue as the top priority, while a parallel team worked on workflow and supply chain issues. To get a handle on the problem, an electrical motor audit was conducted. It identified:

• Flawed repair/replace approach in terms of total cost of ownership. In some instances, pumps were repaired when the purchase of a brand new one would have been cheaper;
• Poor load factors that reduced the expected life of motors from 40 years to 5 years;
• Inappropriate mechanical setups that resulted in frequent shaft failures;
• Overall lack of regard for OEM recommendations of preventive maintenance.

After completing the audit, the team ran idea generation sessions that devised a number of measures to significantly increase the availability of motors and reduce their total cost of ownership. These ideas were fed through the ideas pipeline to ensure their effective implementation.

As a result, equipment maintenance was improved at all levels and repair costs reduced through improved management processes, such as competitively tendering repair work through technically pre-qualified repair facilities. Further actions reduced both motor wear and tear and power consumption.

The total cost reduction was more than $1.1 million of recurring annual gain.

Electric Motor Performance Management Results

Hard Rock Underground Mine – When PIP arrived, the mobile maintenance team was in reactive mode, with machine availability falling across a large fleet. The primary counter-measure at the time was to attempt to resolve the most desperate failures as they popped up.

The initial diagnostic uncovered: facilities in poor condition, high labour turnover, low floor supervision, and inefficient repair processes.

The equipment was in such poor states of repair that an immediate repair campaign was needed to stabilise the equipment before root cause analysis could be done. This was also needed to boost maintenance team morale. This focused action to get the facilities up to scratch showed management was serious about change for the better.

While repairing the top machine problems seemed difficult and expensive initially, the expense was really a “catch-up” on expenditure foregone. Availability also hurt in the very short-term, as the machines were taken out of service for maintenance. Nonetheless, this work provided early positive results, forming a solid base for further work by diminishing subsequent machine failures.

The added equipment stability was then the springboard for building a more universal problem-solving approach targeted at attacking large numbers of smaller opportunities. This approach included designing and implementing a preventive maintenance schedule, improved workflow systems and compliance, proper tracking and supervision, faster diagnostic and repair, and improved communication.

Over a four month period, critical equipment availability increased from below 75% to above 80%, and the average number of loader breakdowns per week was reduced by 40%

Hard Rock Underground Mine - Results in mobile maintenance improvement