Mining Time Usage Models: A Practical Guide & Best Practices

Overview

In modern mining operations, effective mobile asset management relies on a granular understanding of how equipment time is utilised. The Time Usage Model (TUM) provides a standardised hierarchical framework to categorise equipment activity, facilitating the calculation of critical Key Performance Indicators (KPIs) like availability, utilisation, and operating efficiencies. Many mines struggle to adopt a standardised TUM with constant debate and lack of consensus; having a common TUM across multiple operations can sometimes require enormous will to implement.

Contents

1. The Core Time Usage Hierarchy

2. Evolving the TUM: Integrating Operational Technology (OT)

3. Important Note on KPIs driving the Wrong Behaviour

4. Avoid Mining Equipment KPIs that will be Inherently Unreliable

5. Individual Delay and Down Codes

6. Summary and Recommendations

7. FAQ on Mining Time Usage Models

The Core Time Usage Hierarchy

The foundation of the TUM is the systematic breakdown of Calendar Time (CT) into specific blocks that define equipment readiness and state.

1. Total Time and Calendar Time

• Calendar Time (CT): The total period under consideration (e.g., 24 hours). It is the sum of Available Time (AT) and Down Time (DT).

• Decommissioned Time (DC): This is not always implemented but we believe it is important for KPIs that truly reflect an operation’s equipment performance. Time where an asset is removed from the active fleet for long-term storage or disposal. 

• Total Time (TT) is calculated as CT + DC.

2. Available Time (AT)

Available Time represents the period when the equipment is mechanically, electrically capable of performing its intended function or put simply; it's not broken down or on planned maintenance. It is typically further categorised into:

• Utilised Time (UT): The period when the equipment is active and contributing to mining operations.

• Operating Standby (OS): Time when equipment is available but not active due to lack of operator or operational requirement.

• No Scheduled Production (NSP): Time when the asset is available but there is no plan to operate it (e.g., mine closure, plant shutdown, holidays). Note that some mines are tempted to use this category to make certain KPIs look better. This should only be used when no scheduled production is truly planned rather than a last minute pivot on shift

If you have a suitable detail of reliable data, we suggest you also add Productive Time and Non Productive Time. Examples of this are loading (productive) and hanging (non-productive). Avoid doing this if your data isn’t accurate enough.

3. Down Time (DT)

Downtime occurs when equipment is unavailable to work due to planned maintenance or an unplanned stoppage (otherwise known as a breakdown). Key categories typically include:

• Scheduled Downtime (SD): Planned maintenance activities (e.g., PM, pre-PM inspections, component change out).

• Unscheduled Downtime - Asset (UDA): Unplanned mechanical or electrical failures of the machine itself.

A further category which we encourage mines to embrace is to cover downtime not related to core equipment maintenance

• Unscheduled Downtime - Other (UDO): Stoppages caused by factors external to the machine's core function, such as technology failures or logistical constraints.

Evolving the TUM: Integrating Operational Technology (OT)

The rise of Autonomous Haulage Systems (AHS), Fleet Management Systems (FMS), and Collision Avoidance has introduced new failure modes. Traditional TUM models often hide technology failures within general downtime, which can misrepresent the performance of both maintenance and operational technology departments.

Best Practice for OT Classification: MTS recommends isolating Technology Downtime to provide clarity on system reliability without penalizing mechanical availability metrics.

• Functional Failure approach: If a technology system (e.g., CAS or Fatigue Monitoring) is required by site regulations for operation, its failure should be treated as a functional failure (Downtime).

• "Other Down" approach: The failure would be classified under Unscheduled Down - Other.

Scheduled downtime for mining technology should go under “Scheduled Down” however some sites do have a separate “Scheduled Down - Other”. This can introduce complexities for those entering in downs but does bring an ease to downstream reporting. 

Essential Asset Performance Metrics

Using the categories defined above, the following table highlights some of the most common KPIs used in the industry:

Important Note on KPIs driving the Wrong Behaviour

Care really needs to be taken when rolling out the use of KPIs within an organisation. Putting too much emphasis on a certain KPI could lead crews to conduct all manner of obviously wrong behaviours simply to hit a target. Below are two examples we’ve seen at mines in recent years:

Utilisation: Focusing too heavily on utilisation which results on a shift simply running every piece of available equipment to have a high number. (Rather than focusing on operating efficiency and indeed drilling down to look at the split of productive versus non-productive mining activities)

Tonnes per Hour: Crews short dumping in a shift to achieve a ridiculously high tonnes per hour.

Avoid Mining Equipment KPIs that will be Inherently Unreliable

If you have your VIMS/VHMS equipped trucks running a modern fleet management system, you are likely to be able to have highly accurate KPIs for operating efficiency, tonnes per hour per EFH etc. This is because a lot of your data capture will be automated and it will have a deep grain of detail (i.e. tonnes, speeds, activity times). However you won’t be able to replicate this for your ADT fleet where you are just receiving basic data (assuming it has no FMS on it). Therefore be reasonable and manage expectations in what can be measured and benchmarked for your various fleets.

Individual Delay and Down Codes

Care should be taken when selecting your set of delay and down codes. It is important that over complexity is avoided to prevent confusion, “duplicate” codes across multiple categories should be avoided. Here are some tips when creating your delay and down codes:

• Agree across all departments the set of codes

• When setting up in your FMS, ensure you spell check and configure for the right machine classes and exclude from the onboard where possible.

• Avoid the tendency to add new delays and downs in a knee jerk reaction.

• Take care when renaming delays or downs as it's possible you could break some of your site reporting.

• If possible tie to SEMC codes

• Ensure you have appropriate training material including cheat sheets for operators and dispatchers.

• If taking a corporate model, exclude any that are obviously never going to be used at your operation (i.e. you don’t need a snow delay in the tropics).

Summary and Recommendations

Standardising your Time Usage Model is incredibly important for every mining operation; and ideally mining houses should standardise across their multiple operations.

1. Agree on a Standardised, Realistic TUM: Work across departments to define the TUM

2. Avoid Complexity by ensuring you only create a TUM and subsequently KPIs that can be reliably measured with your source data.

3. Automate Data Capture via FMS and onboard telemetry to ensure the accuracy of "Unknown Time" and operational delays.

4. Standardise Reporting across the operation(s) to ensure everyone is looking at the same metrics.
   
   
   

   For sites looking to refine their performance reporting, MTS provides the expertise to align legacy systems with modern industry standards, ensuring your metrics truly reflect operational reality.