The Time Usage Model (TUM), created by the Global Mining Group (GMG), is a tool that helps mining companies break down and understand how time is spent during equipment operation. This model provides a clear picture of how equipment is being utilised. One of the key benefits of the TUM is that it allows for benchmarking, making it easier to compare performance across different operations or against industry standards.

Why use it?

The TUM is a game-changer for optimizing efficiency. By utilizing this model, mining companies can easily identify areas where time is being lost and devise strategies to address these inefficiencies.

One of the biggest advantages of the TUM is its ability to categorize time separately based on different classifications, crucial for generating KPIs that measure the performance of mining operations. These classifications include availability, utilization, and effectiveness. By tracking these metrics, you can gain valuable insights into how available your equipment is, how well it’s being utilized, and the overall effectiveness of your operations.

The TUM encompasses both KPI calculations and time usage elements. To keep this article concise, we will focus on the time usage elements. Subsequent posts will explore each of the key KPIs, such as availability, utilization, and effective utilization.

What are the time classifications?

The TUM begins with Calendar Time, which serves as the foundation for understanding how every hour in a given period is utilized or lost. From there, the model systematically breaks down time classifications based on the equipment's operational status. This structured approach allows businesses to pinpoint exactly where time is being spent, where it might be wasted, and how operations can be optimized for better performance.

Calendar Time:

Calendar Time represents the total amount of time available for equipment operation within a given period, typically measured in hours per year. This encompasses every possible hour that the equipment could theoretically be in use, providing a baseline for all other time measurements.

Scheduled Time:

Scheduled Time refers to the specific periods when equipment is allocated and required to perform designated tasks or operations. This time is planned to align with business objectives and operational goals.

Scheduled Time = Calendar Time − Unscheduled Time

Unscheduled Time:

Unscheduled Time is the period during which equipment is not scheduled for use due to external factors. These can include statutory holidays, planned shutdowns, or a temporary lack of work.

Available Time:

Available Time represents the portion of Scheduled Time during which equipment is in a condition to perform its intended function. High Available Time suggests that the equipment is well-maintained and ready to contribute to operations whenever needed, thus maximizing its productive potential.

Available Time = Scheduled Time – Downtime

Downtime:

Downtime occurs when equipment is required for operation but is not functional due to various issues such as failures, breakdowns, or for scheduled maintenance. Downtime can be triggered by unscheduled maintenance or scheduled preventative maintenance. Reducing Downtime is a primary goal in equipment management, as it directly impacts productivity and operational efficiency.

Operating Time:

Operating Time refers to the period when equipment is actively being used under the control of an operator or an automated system. This is the time when the equipment is fully engaged in performing its designated functions.

Operating Time = Available Time – Standbys

Standbys:

Standbys can be divided into 'Operating Standbys' and 'External Standbys'. Operating Standby refers to instances where the equipment is not operating due to management decisions, such as no operator being available, shift changes, or breaks. External Standby, occurs when equipment cannot be operated due to factors beyond the control of management, such as delayed crew arrival or site-wide weather conditions.

Working Time:

Working Time is the period during which equipment is actively performing its intended functions as assigned, contributing directly or indirectly to production. This metric provides insight into how effectively equipment is being used for its intended purpose.

Working Time = Operating Time − Operating Delays

Operating Delay:

Operating Delay refers to the time when equipment is operational but temporarily stopped or prevented from performing its work due to inherent delays in the operation or due to immediate physical or environmental conditions. Examples of Operating Delays include refuelling, weather-related delays, or waiting for further instructions.

Productive Time:

Productive Time refers to periods when equipment is actively engaged in production-related tasks, contributing directly to operational output. Non-Productive Time, while not directly involved in production, includes essential activities necessary for maintaining safe and effective operations.

Productive Time = Working Time − Non Productive Time

Using the TUM to for Insight:

Implementing the components of the Time Usage Model can yield highly informative insights, such as the 'Truck Time Usage Breakdown' depicted below. This graph illustrates how time is utilized during a standard day shift for each truck within the fleet.

As depicted, starting at 6:00 AM, trucks HT24 and HT25 were scheduled for maintenance. Meanwhile, HT26 and HT24 extended their lunch breaks, and HT5 experienced two breakdowns during the shift.

This visualization provides managers with a clear view of how time is allocated across the fleet. It serves as a foundation for discussions on current usage patterns and highlights areas for potential improvement and optimization.

You may notice that the report displayed above details 'Operating Time' but does not further break it down into 'Working Time' or differentiate between 'Productive' and 'Non-Productive Time.' It's important to understand that the GMG TUM primarily serves as a guideline. In practice, obtaining reliable data for both 'Working Time' and 'Productive/Non-Productive Time' can be quite challenging, largely because it relies on frequent operator inputs. For instance, in typical mining operations, an excavator may be involved in activities such as loading trucks and waiting for trucks. While waiting, the operator must manually select the 'Wait on truck' code, which is considered Non-Productive, and then switch to the 'Loading' code, classified as Productive, when they begin loading. Given that operators switch between these activities multiple times during a shift, it can be demanding for them to change codes each time they switch tasks. Meanwhile, other time usage metrics, such as 'Operating Time,' can be automatically derived from the machine without any need for operator input.