When analysing the major equipment in a mining sequence, time away from an area is just as important as time spent on the task. This time away allows for all other processes to occur that are needed for pit turn around.

1. Presented by:
Christopher Braund
Director
TSV Mining Pty Ltd
M: +61 438 886 473
cbraund@tsvmining.com.au
www.tsvmining.com.au
Total System Value

2. Time Away

When analysing the major equipment in a mining sequence, time
away from an area is just as important as time spent on the task.
This time away allows for all other processes to occur that are
needed for pit turn around - eg:
 Coal mining current strip
 Parting mining current strip
 Drilling preparation next strip
 Drilling next strip
 Blasting next strip
 Etc


These processes usually cannot take place until the major
mining task is out of the area
As production increases in at a mine site by adding more
equipment that cannot work together in the same area, time
away is reduced at a greater rate then the increase in the
production rate

3. Time Away Example

Days
Pit A
Pit B
Pit C
Pit D
Lets look at a single dragline working in 4 pits:
5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
 Here the dragline spends 30 days in each pit
 So the dragline spends 90 days away from a pit for all other activities to
occur

Days
Pit A
Pit B
Pit C
Pit D
What happens if we double the rate of production out of
these four pits by adding another dragline:
5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 2
Dragline 2
Dragline 2
Dragline 2
Dragline 2
Dragline 2
Dragline 2
Dragline 2
 The two draglines spend 30 days in a pit each, and only 30 days away
 The production out of the pit has doubled, but the time for other
processes to take place is only one third of what is was before – 30 days

4. Time Away Example Continued


Days
Pit A
Pit B
Pit C
Pit D
So what affect does this have on the processes that need to
occur while the dragline is away?
Lets say there are 3 processes that need to occur while the
dragline is away: Process X, Y, and Z
5 5 5 5 5
Dragline 1
Z Z Z Z Z
Y Y Y Y Y
X X X X X
5 5
X
Z
Y Z
X Y
5 5 5 5
X X X X
Dragline 1
Z Z Z Z
Y Y Y Y
5 5 5 5 5 5
X Y Y Y Y Y
X X X X X
Z
Dragline 1
Y Z Z Z Z Z
5 5 5 5 5 5
Y Z Z Z Z Z
X Y Y Y Y Y
X X X X X
Z
Dragline 1
5 5 5 5 5 5
Z
Dragline 1
Y Z Z Z Z Z
X Y Y Y Y Y
X X X X X
5 5
X
Z
Y Z
X Y
5 5 5 5
X X X X
Dragline 1
Z Z Z Z
Y Y Y Y
5 5 5 5 5 5
X Y Y Y Y Y
X X X X X
Z
Dragline 1
Y Z Z Z Z Z
Park up time
 Here processes X, Y and Z all have 30 days to complete their tasks and
there is no park up required
5 5 5 5 5 5
Y Z Z Z Z Z
X Y Y Y Y Y
X X X X X
Z
Dragline 1
5
Z
Y
X

5. Time Away Example Continued


From the previous Gantt Chart we can see that the time is
sufficient to allow the tasks to complete their required
activities
Here the task size dictates the process size requirement:

6. Time Away Example - Doubling
Production

Now with the second dragline included and one third of the
time, how do the additional processes look:
BEST CASE DRAGLINE SEQUENCE SCEANRIO:
Days
Pit A
Pit B
Pit C
Pit D
5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5
Dragline 1
X X Y Y Z Z
Dragline 1
X X Y Y Z Z
Dragline 1
X X Y Y Z Z
Dragline 1
X X Y Y Z Z
X X Y Y Z Z
Dragline 1
X X Y Y Z Z
Dragline 1
X X Y Y Z Z
Dragline 1
X X Y Y Z Z
Dragline 1
Y Z Z
Dragline 2
X X Y Y Z Z
Dragline 2
X X Y Y Z Z
Dragline 2
X X Y Y Z Z
Dragline 2
X X Y
X X Y Y Z Z
Dragline 2
X X Y Y Z Z
Dragline 2
X X Y Y Z Z
Dragline 2
X X Y Y Z Z
Park up time
Z Y X Z Y X Z Y X Z Y X Z Y X Z Y X Z Y X Z Y X Z Y X Z Y X Z Y X Z Y X Z Y X Z Y X Z Y X Z Y X
 As Processes X, Y and Z require to complete the tasks in 1/3rd of the
time, they need 3 times the capacity. Their work load has only doubled,
but it is the time they have to complete their tasks that is determining the
rate they require
 The difference between the required rate and the new workload ends up
becoming park up time, here it is 1/3rd of the time

7. Time Away Example - Doubling
Production


The process requirements are now being dictated by the
time to complete the task rather then the size of the task
This leads to peak demands and park up time requirements

8. Time Away Example - Doubling
Production

With the additional dragline in the system, the timing
between the draglines also influences the demand on
processes X, Y and Z:
WORST CASE DRAGLINE SEQUENCE SCEANRIO:
Days
Pit A
Pit B
Pit C
Pit D
5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5
Dragline 1
X X Y Z
Dragline 1
X X Y Z
Dragline 1
X X Y Z
Dragline 1
X X Y Z
X X Y Z
Dragline 1
X X Y Z
Dragline 1
X X Y Z
Dragline 1
X X Y Z
Dragline 1
Dragline 2
X X Y Z
Dragline 2
X X Y Z
Dragline 2
X X Y Z
Dragline 2
X X Y Z
X X Y Z
Dragline 2
X X Y Z
Dragline 2
X X Y Z
Dragline 2
X X Y Z
Dragline 2
PARKED UP
PARKED UP
PARKED UP
X X
X X
X X
X X
X X
X X
X X
X X
Y Y
Y
Y Y Y
Y
Y Y Y
Y
Y Y Y
Y
Y Y Y
Y
Y Y Y
Y
Y Y Y
Y
Y Y Y
Y
Y
Z Z Z
Z
Z Z Z
Z
Z Z Z
Z
Z Z Z
Z
Z Z Z
Z
Z Z Z
Z
Z Z Z
Z
Z Z Z
Z
 In the worst case dragline sequence scenario, the peak demands and
park up times of process X, Y and Z have become more intense
 Process X has been kept at a requirement of 3 times the original, but
processes Y and Z now need to operate at 6 times the original
requirement, and are parked up 2/3rds of the time

9. Time Away Example - Doubling
Production

Here the time demand is being amplified due to the timing of
the dragline activities

10. Time Away



Days
Pit A
Pit B
Pit C
Pit D
From the previous example it can be seen that time away is heavily
affected when adding more processes into a system when trying to
increase production
Time away however will be the inverse of the increase in production if
the increase in production is done with the same number, but larger
processes:
One dragline in 4 pits:
5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
 As before the time on task for the dragline is 30 days, and time away is 90 days

Days
Pit A
Pit B
Pit C
Pit D
One dragline in 4 pits with double the rate:
5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
Dragline 1
 Here the time on task for the dragline is 15 days, and the time away is 45 days
 The production has doubled and the time away has halved
Dragline 1

11. Time Away



The previous examples were done for a dragline, but the
principal is the same for any major operating equipment in
the system that cannot work together in the same area
If production doubles at a mine site, and if the equipment
doesn’t double in size and remain the same number or work
together in the same area, then the time away will end up
being affected, which will affect the other processes that
need to occur
What is happening here is that the other processes
requirement is not relying on the size of the task, but the time
it has to do it

12. Always customised – no two sites are
the same
Thank you
Total
System
Value