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Aggregate Audit Tutorial

A brief case study on the impact of a week long site audit

Can a one week site audit make that much of a difference?

It was a fair question safety and production leaders at an aggregate mine in the Western United States asked Meyvn Global this past year. The sites mine operations routinely offers training, conducts site audits and puts an emphasis on continuous improvement. Even with these efforts to improve employees skills in core mining activities, many of these efforts netted marginal sustainable improvements in performance, production, job efficiencies and safety.

With an already present emphasis on training, auditing and continuous improvement, how much of a difference would a well designed Meyvn audit make in just a week?

In June of 2016, Meyvn’s Director of Task Improvement Frank Dudley, was brought in to answer that question. Frank’s primary goal was to assess the current state of this small aggregate mine seeking insight into what can be done to improve regulatory compliance, general safety, equipment performance and site productivity.

Within 5-days, Frank was able to both identify key opportunities for improvement as well as make an immediate impact that netted the aggregate mine a healthy ROI. This tutorial is focused on explaining the work completed by Meyvn Global through an analysis of what problem areas were found and how they were ultimately fixed.

We will focus on the auditing process used and detail each step so your site can follow this process next time an audit is conducted.

In this tutorial we will cover:

  1. Production Auditing
  2. Equipment Auditing
  3. Safety Auditing
  4. Auditing Best Practices

This tutorial will be of use to anyone looking for insight on how to best audit their operation. We will review the areas of focus and the recommendations provided that describe major improvement opportunities.

With the interest of confidentiality all names and locations cited in the report have been changed. All statistics, recommendations and findings however are 100% accurate.

Section #1: Production Auditing

The main focus of the project was to identify opportunities to improve production. The site that was audited is relatively small in scale.

With only 4-trucks and small loading equipment, how much improvement was really possible?

The site utilized 4-785C CAT trucks, 2-780 CAT loaders, 1-D7 track dozer, 1-C4 trackhoe and 2-rented rock breakers. The machinery was old, but in good condition. The mine is well established with a CAT maintenance contractor on site.

The site consists of 12-day shift employees and 6-night shift employees. The site utilizes a portable jaw crushing system with dual screens and dual cones. There is a drill and blast functionality that is contracted out.

With this size of site, we focused on 14-critical areas with regards to production opportunities. Each area receives a ranking on a scale from very poor to world class. Each of the 14-critical areas captures detailed notes highlighting specific reasons for why the ranking was provided where it was.

The 14-areas consist of:

  1. 1. Daily Plan / Line Out / Start-Up
  2. Maintenance Information & Maintenance Area
  3. General Hazard Identification
  4. Pre-Operation and FLRA’s (Field Level Risk Assessments)
  5. Team Dynamic
  6. Equipment Performance
  7. Road Conditions
  8. Intersections and Corners
  9. Radio Communication
  10. Dumps / Stockpiles
  11. Signage
  12. High Wall Conditions
  13. Digging Conditions (Fragmentation)
  14. Close Out / End Of Day Activity

During the audit, there were 4-major opportunities identified for production improvement. These 4-major opportunities are consistently found during Meyvn audits and should be a focal point for your next site audit.

Area #1: Widening Bottleneck Areas

There is a section of haul road close to the loading area that created a slight delay. This delay totaled 28-seconds per cycle. Minimal delays are often overlooked. With an ever adapting operation it becomes difficult to ensure haul roads possess the right conditions for optimal performance. However, haul road impact does a lot more than just damage tires.

This 28-second delay per cycle, over the course of a shift, leads to a loss of 200 tons. Missing out on 200 tons per shift leads to a loss of 75,000 Tons Per Year.

When auditing your site pay special attention to both road width and road conditions. If trucks have to slow down due to uneven ground or pot-holes, this will significantly decrease haulage time. The 10-30 second delays, compounded over the number of trucks and number of routes will surprise you. The losses due to haul roads is prevalent.

The amount of time it takes to fix the road conditions far outweighs the loss in cycle time.

While conducting your site audit watch for any backup or delays with your mobile equipment. Add up the number of seconds for each delay and then multiply that number over the course of a shift.

Area #2: Shorten Staging Distance

Just like with haul roads, the seconds lost due to staging further away than necessary adds up to thousands of tons being lost a year.

13-second delays were common during the staging part of the cycle. These 13-second delays were solely caused by bad habits adopted by the operators. Fixing staging distance is a quick / easy training opportunity that has an immediate impact on production.

A 13-second delay, every load, leads to a total loss of 12-minutes per shift. With the haul distance at the mine audited this equates to 100 tons being missed each shift.

Missing out on 100 tons per shift leads to a loss of 36,500 Tons Per Year.

At most aggregate locations, it should take no more than 5-7 seconds for each truck to properly stage. Proper staging ensures a thorough process and yields more tons.

Area #3: Load Time Delays

To go along with the theme of little errors compiling to cost big dollars, we focused a lot of energy on tracking the delays associated with the loader operators.

One of the biggest deterrents of production is re-work. Doing the job correctly, the first time, has a massive impact on the overall production process. Most of the delays cited with the loader operators had to do with re- handling materials and spending too much time identifying an ideal dig area.

We calculated over 2-hours of production time lost each shift due loader mistakes.

These loader mistakes add up to a loss of: 317,000 Tons Per Year.

When conducting a site audit count the number of times a loader operator drops a load and the time it takes to fix the mistake. It is no surprise that loader/shovel errors contribute to missed production opportunities, but the magnitude of the effects from these errors are often surprising.

Area #4: Poor Fragmentation

The biggest opportunity identified on the production side was with the fragmentation of the material. The fragmentation was so poor that the crusher is only producing 60% of what it should be.

The over sized rocks that spill onto the haul roads have produced thousands of dollars of repairs and cause fill factors of the trucks to only be 65%. Having a 65% fill factor vs. 100% is literally the difference of 1,000,000 Tons Per Year

Fragmentation is something that is often expensive to moderate. Using contractors to drill and blast is time consuming and does not guarantee better digging. It might not make sense for your operation, but it is something to be conscious of and audit. If your missing out on millions of tons of production due to low crusher output & poor fill factors it might make sense to look into.

When Conducting Your Site Audit... It is important to be as thorough as possible. Paying attention to every single detail is essential. Use the scale below to measure each of the 14-focus areas described on page #3. To the right is a section from the report generated for the western aggregate mine.

Section #2: Equipment Performance:

The following chart is what we use to complete the equipment side of the audit. One of these reports should be done for each operator.

The metrics show that there is a significant opportunity for operator improvement.

Capturing the type of digging and adjusting the possible times is important. Knowing what the average cycle time, fill factor and load time should be for both good and bad digging conditions is important.

How close of attention are you paying to your equipment performance? Do you know what the average tonnage output should be from each machine? Do you measure the average production times of your people and know where training opportunities exist?

The difference between a competent operator and a proficient operator can be calculated in the millions of dollars. Good operators can produce significantly more, improving your organizations bottom line.

Knowing what the benchmark times should be at site, for each piece of equipment, and then measuring your operators to those times, is a best practice that will rear high ROI’s. Targeted training cuts down on training time and can immediately boost your output.

Going from 14 loads a shift to 21 loads a shift (which is very achievable at the site we audited) would produce more than 1,500,000 tons per year.

In conjunction with measuring the operators capability, be sure to also measure attitude and behavior. If an operator has a willing attitude, and the right attributes, then training can improve capability. If there is no desire to improve or learn, training might not have an impact. You can’t teach those who don’t want to learn.

Section #3: Safety Auditing:

On day 3 we performed a MSHA mock inspection. We photographed and documented every infraction identified. Our through investigation of the operation uncovered numerous safety hazards that MSHA would have cited.

We also found some serious hazards that could have led to serious injuries. These hazards were documented and fixed immediately. More than 40—safety hazards were corrected while at site, both reducing the danger as well as increasing compliance.

The most common hazards identified were:

Housekeeping - This was not surprising as housekeeping is one of the most written MSHA citations and common safety infractions on site. We found 30-difference cases of housekeeping. This often leads to slips, trips and falls.

Guarding - There were many problems with guarding either not being used where it should, or used, but out of compliance. Improper guarding can create life threatening hazards.

Berms - Berm failure is one of the leading causes of fatality at mine sites. There were multiple sections were the berm was not in compliance. This was fixed immediately.

Electrical - Improper labeling, electrical cords being out of date or damaged and electrical hazards were commonly found around the site.

There were more than 40-infractions identified on-site. Depending on the MSHA inspector the severity of these infractions could have even been worthy of a D-Order. Averaging $750 per citation (which is a conservative number) the total savings from MSHA citations was $33,750.00 (Prevented In Penalties)

Area #4: Auditing Best Practices

The final section of this tutorial documents some of the best practices to follow when conducting a site audit.

Practice #1: Train During Audit

While on-site we saw an opportunity to implement a tandem loading technique that would improve production. We were able to work with the operators during the audit to test out this process. The results:

  • Single Loading Avg. Haul & Load = 8:39
  • Tandem Loading Avg. Haul & Load = 5:55
  • Difference Per Shift = 2,400 Tons

Making immediate impacts during the audit not only helps justify an immediate ROI, but also provides an opportunity to test out the recommendations you plan to make. People are often more willing to participate in training when they know an audit is being conducted. If operators know the focus is more on testing out a new technique, versus correcting bad behavior, they will buy in.

Practice #2: Have Thorough Materials

A good audit can ONLY be completed with good, through tools. Having proper auditing guides, checklists, and metric outlines is a must.

Your auditing materials need to be extremely detailed to ensure that every little thing is being checked while on site. We have designed ”smart” documents that are filled out using simple check boxes and likert scales. We can put actual numbers to the sites performance. Use OSHA / MSHA regulations as the outline for what to include.

Practice #3: Use Outside Eyes

The more time we spend on site the less likely we are to be objective. Using outside consultants or people within the organization who work at different locations is always a good idea. Taking someone from the pit into the process area and vice versa also helps.

Practice #4: Focus On Fixing One Thing

During audits we often want to identify and change everything all at once. There is only so much change possible at a time! Focus on having one win at a time and then let that momentum snowball.

Working with one operator to improve the number of loads per shift from 20 to 21 is a great fix that will have a huge ROI. That one extra load a shift can be 240 additional loads per year!

Practice #5: Prevent One Injury From Occurring

If the audit can prevent one injury from occurring it would more than pay for itself.

Liberty Mutual Insurance Group found that $1 of safety training returns $3 in savings. That is a sizeable ROI.

Practice #6: Stop One Mistake

Mistakes, even the little ones, add up to negatively affect safety, productivity and efficiency.

When auditing a site look for the mistakes, document them and rectify them quickly. The longer it takes to address the mistakes found in an audit, the less likely they are to be rectified.

Practice #7: Set The Right Tone

Audits can come off as fear based events that are geared at identifying everything wrong about the site. Ensuring those involved set the right context and focus on continuous improvement, versus pointing fingers, will make a big difference in how an audit is received.

It is also more than OK to document all of the good things happening at site to ensure those behaviors get reinforced and recognized. Positive reinforcement during an audit can have a very substantial impact. 


Conducting site audits is a great start to improving the way the site is run. Meyvn has conducted hundreds of audits at sites all over the world. We would love to help you in your auditing process and look forward to any future opportunity.

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Meyvn Global (pronounced MAY-ven) is an international training and development firm that is Unlocking Human Potential. We are unlike any training consultants you’ve ever worked with. In Leadership Training and Personnel Development we’ve cultivated a reputation for being fun and engaging. But just between us, the fun factor is only the means to the end; our experiences are known to raise retention rates to 75%. That’s up to 65% more knowledge retention than the alternatives. You know- the ones with the nasty habit of causing drowsiness and boredom.