FMS Insight Monthly Cycle Analysis

FMS Insight supports continuous improvement by assisting with a monthly review. We suggest that approximately once a month, all stakeholders review the operation of the cell and decide on potential improvements. The improve an FMS documentation goes into more details about how to make the most of these efficiency calculations.

Screenshot of choosing analysis month

At the top of the page are two radio buttons allowing you to analyze either the last 30 days or a specific calendar month.

Machine Cycles

Screenshot of station cycle chart

The machine cycle chart displays a point for each program cycle. The cycles can be filtered by a specific part, a specific program, a specific machine, a specific pallet or a combination. The x-axis is the days of the month and the y-axis is cycle time in minutes. The cycle time is the wall clock time between program start and program end of the machine. The legend at the bottom shows which colors correspond to which stations, and by clicking on stations in the legend you can enable or disable the viewing of specific stations. By clicking on a point you can obtain details about that specific cycle in a tooltip and open the material card for the cycle. Finally, the chart can be zoomed by clicking and dragging.

When a specific part and specific program are selected, a gray background and black horizontal line are shown. The gray background is calculated to be the statistical median and deviation of the points; the middle of the gray band is the median of the program time and the width of the band is determined by calculating the median absolute deviation of the median (MAD). In contrast, the horizontal black line is the expected cycle time entered during scheduling and sent in the scheduled jobs. Thus if the horizontal black line differs significantly from the middle of the gray band, this means that likely the expected time used in the simulation and scheduling is incorrect.

The example screenshot above is an example of a part program which looks good. We see that almost all of the machine cycles are around 40 minutes, within the gray band and the horizontal black line and there are only a couple machine cycles significantly longer than 40 minutes which likely come from program interruptions, tool problems, etc. Since there are only a couple outlier points, we might instead conclude that it is not worth the effort to spend a large amount of time focusing on this part. If instead the graph showed many points outside the gray band and longer than 40 minutes, it would be worth it to investigate and improve the part program and tooling.

Screenshot of station cycle table

The cycles can be toggled to display the raw data in a table instead of a chart. The table can be filtered, sorted, and restricted to a specific date range. The resulting raw data can be copied to the clipboard to be pasted into a spreadsheet for further analysis.

Load/Unload Cycles

Screenshot of load station cycle chart

The load/unload cycle chart displays a point for each load or unload event. The x-axis is the days of the month and the y-axis is time in minutes. The cycles can be filtered by a specific part or pallet. The chart will display one of three possible times for each operation: "L/U Occupancy", "Load (estimated)", and "Unload (estimated)".

The "L/U Occupancy" chart displays a point for the wall clock time that the pallet spends at the load station; the time from the pallet arriving at the load station until the operator presses the ready button. This is the time that FMS Insight collects and stores so this chart displays the actual raw data collected.

Despite being the actual data FMS Insight collects, the "L/U Occupancy" chart is hard to use to determine if there are problems or slowdowns in loading a specific part. The recorded time is the wall clock time from pallet arrival to departure so includes all the operations which occur at the load station which might include a load and an unload or just a load or just an unload. Thus, FMS Insight attempts to split the wall clock occupied time of the pallet at the load station among the various operations such as loading or unloading that occurred.

For each cycle, FMS Insight splits the time the pallet spends at the load station among each piece of material being loaded, transferred, or unload. To do so, FMS Insight uses the list of material loaded/unloaded/transferred and calculates the expected time the operation should take based on the values entered into the scheduled jobs. The expected time is then used to calculate a percentage consumption for each material, and this percentage is then applied to the actual wall clock time of the pallet occupancy. For example, consider an operation where part aaa is loaded and part bbb is unloaded. The schedule says that the loading of aaa should take 5 minutes and the unloading of bbb should take 8 minutes for a total time the pallet should spend at the load station of 13 minutes. Now say that the pallet actually spent 15 minutes at the load station. The load of aaa is expected to consume 5/13 = 38% of the cycle and the unload of bbb is expected to consume 8/13 = 62% of the cycle. The 38% is multiplied by the actual wall clock time of 15 minutes to give approximately 5.8 minutes for the load of aaa. Similarly for the unload of bbb, 15 minutes times 62% is approximately 9.2 minutes. Note how the "extra" 2 minutes (15 minutes compared to 13 minutes) for the entire cycle is divided among both the load and the unload operation. This calculation is repeated separately for each load/unload cycle.

The result of FMS Insight's estimated splitting is graphed in the "Load Operation (estimated)" and "Unload Operation (estimated)" charts selected in the top-right corner. The screenshot above shows the "Load Operation (estimated)" chart. For each load/unload cycle, FMS Insight splits the time as described above and then plots a point with the y-coordinate the calculated time, filtering the data to a specific part and/or pallet. (In the example from the previous paragraph, the points would have y-coordinate 5.8 and 9.2 minutes.) Exactly like the machine cycles, FMS Insight calculates the median and median absolute deviation of the points and plots them as a gray band in the background. Finally, the expected time entered into the scheduled jobs is graphed as a horizontal black line.

Pallet Cycles

Screenshot of pallet cycle chart

Select a pallet from the combo box in the top-right. Once selected, all pallet cycles are displayed. The x-axis is the days of the month and the y-axis is the pallet cycle time in minutes. A pallet cycle time is the wall clock time from when a pallet leaves the load station to the next time it leaves the load station. This will therefore include cart transfer time, buffer time, machining time, and load/unload time. By clicking on a point, you can obtain more information about the pallet cycle in a tooltip. Similarly to the station cycle chart, the pallet cycle chart can be zoomed by clicking and dragging or the zoom range can be manually set via the button in the bottom-right.

The pallet cycle chart is best used to determine if the cell is running lean and validate the daily allocation and scheduling technique to determine if there are traffic jams occurring in the pallets. In a lean, healthy cell, most pallet cycles should be low and reasonably consistent. If pallet cycle times vary wildly, there is likely traffic jams or other flow problems.

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