U_GAP was jointly developed by McAlpine-B and Brian Nicholls Mining and was released to longwall mines last week.
Why develop U_GAP?
"Well, utilisation is an important aspect of overall mine productivity," says McAlpine-B's Graeme Baird. "For example, a 1% increase in utilisation for the average Australian longwall operation results in a $3.3 million increase in revenues."
"Both Graeme and I are a bit obsessed by utilisation," says Brian Nicholls. "Improved utilisation results in substantially improved cash flows so and we wanted a way for mine managers and owners to be quickly able to assess their own utilisation performance against best practice without a whole lot of technical jargon.
"U_GAP only requires very basic information, the type of information that mine managers would have at their finger tips. For example, longwall tones produced in last year, tonnes per shear, shears per operating hour etc. In 10-15 minutes they can compare their own utilization to that of a best practice mine.It is critical that when operators are using U_GAP that they are honest with themselves when inputting the data."
Technically, utilisation is defined as the time spent producing coal divided by 8760 hours (ie the number of hours in a year). Most best practise benchmarks reflect this type of calculation. However, such a measure significantly understates the utilisation of mines that only operate five days per week and/or have very short longwall blocks as they have more change-outs per year.
To overcome this problem, Baird and Nicholls developed the concept of "production utilisation".
"Production utilisation refers to the time that the mine actually produces divided by the total scheduled or planned time for production or maintenance activities. This allows us to meaningful compare the utilisation of seven-day and five-day mines. Time taken for change-outs is excluded from the analysis so it is meaningful to compare mines that have short and long block sizes," Baird said.
U_GAP can be used to calculate utilisation for any time period (eg weeks, months or years) but it makes sense to start with the last full year of operation for two reasons. Firstly, utilisation varies significantly on a month by month basis. Secondly, and more importantly, most best practice benchmarks are calculated on an annual basis so it makes sense to compare like with like.
What could managers do if they are dissatisfied with utilisation performance?
"U_GAP produces a summary sheet that outlines all the assumptions made in calculating a longwall unit’s actual utilisation," Nicholls said. "Print that out and give it to mine managers, longwall and maintenance superintendents and ask them what they think.
“Managers' first reaction to a benchmarking exercise is to question the figures, especially if the numbers do not go their way. That’s fine and is to be expected. We suggest that they play around with U_GAP. For example get the longwall management team to run some optimistic and pessimistic scenario’s then come back to you to determine actual results and realistic objectives for the longwall business,” Baird said.
“The point is that U_GAP is just a tool that will help you start the debate about utilisation in your organisation. Ultimately you want to know if there is a problem with utilisation and, if so, what to do about it. Brian and I can help with both these issues if required.”
For more information or a copy of U_GAP contact Brian Nicholls, niminco@acenet.com.au or Graeme Baird, gbaird@mcalpineb.com.au.
* Brian Nicholls and Graeme Baird are principals of Brian Nicholls Mining and McAlpine-B respectively.
