RPS Earthworks - Work Order Productivity Chart
Once a work order has been initiated, the machines commence work and start generating production quantities. Work that is executed is divided into the two shifts based on the start and end times defined for the shift crews.
As the machines work, they capture blade elevation information from the GCS900 machine control system and package the data into TAG files that are sent back to the RPS Earthworks System over the wireless network.
The TAG files are then harvested by the RPS Earthworks Production Server (Raptor) and compiled into a multidimensional database that can be mined for information about the elevation state of the surface within the limits of the work order boundary.
In addition to the machine data, the site will be flown using a drone periodically to capture a survey surface at a specific date and time, that can be used to supplement the machine data - for example in the backfill operation - the backfill process is fed primarily by the stacker conveyor which lays the material in the backfill area on a continuous basis. So the volume change over time is only monitored, when the backfill reaches an elevation close to its target and the GCS900 equipped dozers engage to spread the material and grade the final surface. In between time, if the site is surveyed using a drone or traditional means (GPS or Total Station) or using a terrestrial scanner, that data can be uploaded as a Survey Surface to supplement the machine data in the system.
The productivity metrics analysis, monitors the change of the surface over the duration of each shift to monitor the change in cut or fill volume during each shift of production. Since the backfill process is not monitored continuously, it will give you volumes in steps that may or may not accurately reflect the work completed each shift, however it will accurately reflect the work completed to date and over any given time range.
Where the machines are executing cut to fill or grading operations, if the machines are the primary distributor of material, you will get an accurate reflection of productivity of each shift crew over time.
The productivity report currently looks as follows and has the following controls to manage the content of the report. Note that we are changing the colors so that all Cuts are Red and all Fills are Blue (shades of red or blue for Crew 1, Crew 2 and Totals) to improve the clarity of the report.
In general the report is showing the production volumes of cut and fill completed by each shift crew on either a daily basis throughout a week or on a weekly basis throughout the life of the work order.
Time Range Selector
The options to select here include
- This Week - this shows the daily production results by shift crew and totals for the current week in progress on a daily basis.
Note that the chart shown was created using only surveyed surface information at specific dates and times, so does not reflect the work completed by Crew 1 and Crew 2 accurately - if this data is supplemented by machine tag file data throughout the work order execution process, it would more accurately reflect shift crew productivity.
Note also that in this situation, the survey was flown on a Tuesday and captures all of the production completed since the last flight in the prior week which was also flown on a Tuesday - so each volume reported is for the entire prior week of production back to the previous survey. Note the intent of the survey surfaces is that they would supplement the machine data that is being generated continuously not that the survey surface would be the only source of information - because the intent is to mix Survey and Machine data in the results, the method of calculation using the survey surfaces only is not ideal because it does not spread the computed production over the days elapsed since the last survey.
- Last Week - this shows the daily production results by shift crew and totals for the last complete week of production on a daily basis.
Again the chart shown here is based on a single weekly surveyed surface at a specific date and time and does not accurately reflect the productivity of the shift crews.
- Entire Work Order - this shows the weekly productivity results by shift crew and totals for the entire work order on a weekly basis.
Again the chart shown here is based on a single weekly surveyed surface at a specific date and time and does not accurately reflect the productivity of the shift crews.
Report Selector
The report selector provides two options
- Productivity Toward Goal
- Cut / Fill Shift Start vs End
Within these two options you can also select which metrics that you want to present from the following options
- Total Volume
- Average per Hour
Productivity Toward Goal
For each time period in the chart (day or week) you will find up to three result blocks that show the Cut and Fill volumes achieved by each of the two shift crews and the total cut and fill volume for the entire time period. If you hover over the result block the actual cut and fill numbers for the shift crew or totals will be displayed to you.
The volume calculations in this option are based on the following formula
(Starting Surface - End of Previous Shift Surface) - (Starting Surface - End of current Shift Surface)
Example 1
If you have a starting surface that is a level plane of elevation 100, and at the end of the previous shift there is a pile of material on that plane in location A. During the shift you move the pile of material from location A to a new location B. In the computations for this method, you will get a net 0 volume progress towards your goal because the fill at the start of the process = the fill at the end of the process so there is no change of Fill or Cut towards your goal for the task.
Example 2
If you have a starting surface that is a level plane of elevation 100, and at the end of the previous shift the level plane is as it was at the start of the work order. During the shift, the crew dig a hole in one area and place that material as fill in another area. In the computations for this method, you will get a Cut Volume and a Fill Volume progress towards your goal because there was a change in Cut and a change in Fill during the shift period.
Example 3
If you have a starting surface that is a level plane of elevation 100, and at the end of the previous shift the level plane is as it was at the start of the work order. During the shift you dig a hole and then backfill it in the same shift. The volume would return a net 0 volume for the work.
If however in shift 1 you dig the hole and stockpile the material excavated and in shift 2 you backfill the hole using the material from the stockpile, you would then report a cut and fill volume in Shift 1 and a cut and fill volume in shift 2 towards your goal which in reality could be erroneous in the big picture of the Work Order because you moved the material twice. However in this situation it is work that you carried out.
Note that depending on the timing of the computations (in this case start and end of shift) - it is therefore possible and quite likely that you could compute volumes that do not match the overall plan for the task if double or higher movements of material take place in the execution of the task. You can therefore not guarantee 100% that the work carried out was “meaningful” work in the context of the Work Order.
When we compute the burndown charts for the Work Order we are always comparing the Date and Time point with the starting surface point so that we can see the net change in the surface over the elapsed time. If there are double or triple movements of material they are ignored in this computation as it is simply the current date / time - starting surface in all cases.
If the work order results include continuous machine data from both shift crews, then the results allow you to directly compare the total production of each shift over the time period being displayed as well as the total production of the work order.
If the result data are derived from surveyed surface updates only, then the data for each shift crew will not be available and the survey results will generate a cut / fill quantity from the last measured survey and put the results into the shift crew that would have been working at the date and time of the surveyed surface.
Cut / Fill Shift Start vs End
This method of computation uses the above formula
Shift End Surface (date/time) - Previous Shift End Surface (Date/time)
Using the same examples as above
Example 1
At the start of the Work Order you have a level plane of elevation 100 with a pile of material on that plane in location A. During the shift you move the pile of material from location A to a new location B. In the computations for this method, you will get a cut volume and a fill volume because the pile was cut in location A and filled in location B.
Example 2
At the start of the Work Order you have a level plane at elevation 100. During the shift, the crew dig a hole in one area and place that material as fill in another area. In the computations for this method, you will get a Cut Volume and a Fill Volume because there was a change in Cut (the hole) and a change in Fill (the pile) during the shift period.
Example 3
At the start of the work order you have a level plane at elevation 100,.During the shift you dig a hole and then backfill it in the same shift ending with the same level plane at elevation 100. The volume would return a net 0 volume for the work looking like 0 productivity.
If however in shift 1 you dig the hole and stockpile the material excavated and in shift 2 you backfill the hole using the material from the stockpile, you would then report a cut and fill volume in Shift 1 and a cut and fill volume in shift 2 which in reality could be erroneous in the big picture of the Work Order because you moved the material twice. However in this situation it is work that you carried out and it would be fully captured as work completed.
The same notes apply to these computations, when you look at tasks at a “micro” level, you can see more and more detail about what actually happened, however the sampling rate would need to be every second in order to capture all details accurately. As you move the computation points out to hourly, bi-hourly etc. then the granularity of the results is reduced and smoothed.
To accurately compute the net status of your Work Order you need to use the burndown chart that compares the current surface with the starting surface on an hourly basis, while this does not capture all double movement of material, it does give an accurate assessment of the change in cut / fill over time, however overexcavation and backfill or overfill (surcharge) and cut back or simply double movements of material will only be partially captured based on the hourly computation interval unless the transition points happen to fall exactly at or around the hourly interval computations.
Total Volume
The total volume shows the entire cut and fill volume quantity moved by the shift crew over each time period displayed by the chart (Days or weeks)
Average per Hour
The average per hour shows the total cut and total shift by shift crew or totals for the week generated per hour. A shift crew working 12 hours per day, 7 days per week has 84 hours (7x12) of production. The volume for the shift crew period (day or week) is divided by the number of production hours to derive the average volume per hour.
Note that the Total Volume and Average per Hour results are for each full period of production, depending on the settings that have been applied to the chart. If the results have been derived purely from Survey Surface data, and e.g. if the surveyed surfaces are applied on a Tuesday of each week, then each survey surface will generate a change in volume of cut and fill from the prior survey and that change in volume is applied 100% to the current time period (day or week). No attempt is made to distribute the volume derived from a surveyed surface over the time elapsed since the previous surveyed surface or between the crews applied to the work order because the intent of the system is that the machine data would be available continuously for all Work Orders.