This topic describes the calculations used by the gadgets you add to dashboards in iMonitor Designer and the filters each gadget/gauge supports.
Active batch average dwell time
| Filter supported: Operation Alias |
|---|
Looks at the most recent x number of units processed at the specified operation alias for the batch (x is configurable, the default is 10). The next operation in the flow for the active batch is determined. For each unit, an attempt is made to locate a WIP record for the same serial number at the next operation. If found, the Time Completed at Operation 1 is subtracted from the Time Started at Operation 2 for that same unit and the difference is stored. If not found, that unit is skipped and the process is repeated using the second most recent unit to leave Operation 1. The process continues until x calculations are completed successfully or the algorithm runs out of Operation 1 WIP records. The average of all x differences is returned.
Unit 3: Op1 Time Completed = 2:05 Op2 Time Started = 2:15Dwell = 2:15-2:05 = 10 minutes
Unit 2: Op1 Time Completed = 2:08 Op2 Time Started = 2:17Dwell = 2:17-2:08 = 9 minutes
Unit 1: Op1 Time Completed = 2:20 Op2 Time Started = 2:25Dwell = 2:25-2:20 = 5 minutes
Average Dwell Time = (10 + 9 + 5) / 3 = 8 minutes
Active batch effective time per unit
| Filters supported: Operation Alias, Operation Template, Workstation |
|---|
Subtracts the Time Started of the very first WIP record at the operation for the active batch from the Time Completed of the most recent WIP record for the same operation, then divides that result by the total number of WIP records for the batch at the operation. The result is the average production rate across the whole job, including any down time related to breaks or other reasons.
Example: If a job has 200 units in it, and 75 have been processed.
Unit 1: Time Started = 11:04 am
Unit 75: Time Started = 4:25 pm
Effective Time Per Unit = (4:25 pm – 11:04 am = 5 hours, 20 minutes) / 75 = 4.267 minutes/unit
Active batch units per hour
| Filter supported: Operation Alias |
|---|
Subtracts the Time Started of the second most recent WIP record for the active batch at the operation from the Time Started of the most recent WIP record for the active batch at the operation. Takes the result (snapshot time per unit) and applies this formula to convert to units per hour. Units per Hour = 3600 / (snapshot seconds per unit).
Example:
Unit 1: Time Started = 5:35 pm
Unit 2: Time Started = 5:29 pm
Active Batch Units per Hour = 3600 / (5:35 – 5:29) = 3600 / (360 seconds) = 10 Units/Hour
Active job components per hour
| Filter supported: Operation Alias |
|---|
Looks at all units processed and sums components placed and sums actual cycle time from the ItemSummary table to formulate components per hour. Components per hour = (total components placed / total cycle time) * 3600.
Example:
Unit 1: Components Placed = 136, cycle time = 2 minutes
Unit 2: Components Placed = 403, cycle time = 6 minutes
Active Batch Components per Hour = ((136 + 403) / (2 + 6)) * 3600 = 4,042.5 Components/Hour
Average cycle time
| Filter supported: Operation Alias |
|---|
Averages the cycle time of the most recent x number of units for the active batch for the point (x is configurable, default is 10). Cycle Time for a pair of units is defined as (Time Unit 2 Entered Point) – (Time Unit 3 Work Start at point). The calculation uses the Time Started field of the ItemSummary table.
Example:
Unit 1: Time Started = 5:35:00 pm
Unit 2: Time Started = 5:36:30 pm
Unit 3: Time Started = 5:37:50 pm
Cycle Time (1) to (2) = 90 seconds – Cycle Time (2) to (3) = 80 seconds
Average Cycle Time = (80 + 90) / 2 = 85 seconds
Average working time
| Filter supported: Operation Alias |
|---|
Averages the cycle time of the most recent x number of units for the active batch for the point (x is configurable, default is 10). Working Time for a single unit is defined (Time Work Complete at point) – (Time Work Start at point). For browser WIP records, TimeWorkStart is the same as TimeStarted and TimeWorkComplete is the same as TimeCompleted. For xLink machine data, this is not necessarily the case, it could be that a machine completes work on a unit, but because it is blocked by a downstream machine, it does not leave the machine for another minute or two.
Example: Given a number of past units setting of 2
Unit 2:
Time Started = 5:35:00 pm, Time Work Start = 5:35:10, Time Work Complete = 5:38:00, Time Completed = 5:38:45, Cycle Time = (5:38:00 – 5:35:10) = 170 seconds
Unit 1:
Time Started = 5:39:50 pm, Time Work Start = 5:39:55, Time Work Complete = 5:42:47, Time Completed = 5:43:55, Cycle Time = 172 seconds
Average Working Time = (170 + 172) / 2 = 171 seconds (2 minutes 51 seconds)
Active batch completion duration
An estimate of the time it will take to complete the job at the selected Operation and not to complete the entire route of the batch.
| Filter supported: Operation Alias |
|---|
Determines the number of needed units for the Operation (job quantity – distinct WIP count) + scrap overage. This determines the production rate. If the Time Standard option (default) is set to Real-Time the production rate is calculated from the average cycle and will look at the last 10 units processed. If you select Estimated Time, the production rate is calculated from the estimated cycle times. The final calculation is the product of the production rate and the total units needed.
Example: If using 'Real Time' for the 'Time Standard' option with a job quantity of 5 boards and only 3 boards have been completed so we need 2 more units.
Unit 1: Time Started = 1:06
Unit 2: Time Started = 1:082 minutes
Unit 3: Time Started = 1:113 minutes
Average Production Rate = (2 + 3) / 2 = 2.5 minutes
Completion Duration = 2.5 minutes * 2 = 5 minutes
Job processing time detail
| Filter supported: None |
|---|
Displays the serial number, processing time and target time of x number of units processed or in process for all operations of the active batch (defaulted to the top 5 most critical units). Processing Time represents the actual cycle time and also includes the current processing time of any unit started and has not yet been completed. Target time is the estimated cycle time from the Time Standards. The most critical units are the ones with the least time remaining. The key idea behind this output is to show that the time processing is going beyond the time it should take to process. The gauge can be set to show only the active unit which displays only one unit which is the most critical.
Example:
Current time is 9:00am and estimated time to build 1 unit is 6 minutes.
Unit 1: started at 8:25 am, finished at 8:30 am = 5 minutes
Unit 2: started at 8:31 am, finished at 8:40 am = 9 minutes
Unit 3: started at 8:42 am, finished at 8:48 am = 6 minutes
The display would be:
Serial Number | Processing Time | Target Time |
Unit 2 | 00:09:00 | 0.00:05:00 |
Unit 3 | 00:06:00 | 0.00:05:00 |
Unit 1 | 00:05:00 | 0.00:05:00 |
Unit 2 has gone over the time expected.
Active job completion
| Filter supported: Operation Alias |
|---|
Subtracts the number of units that have failed from the number of units processed through the operation to derive at the number of completed units. If the number of completed units is greater than the job quantity, the completed quantity is reduced to the job quantity.
Active Job DPMO (IPC 9261)
Filter supported: Operation Group Template
Calculates defects per million opportunities at the operation level. IPC 9261 DPMO is (the total defects collected / (the unit count * the operation opportunities) ) * 1,000,000.
Example:
Unit 1: 11 defects
Unit 2: 0 defects
Unit 3: 5 defects
Opportunity count is 1000.
DPMO is (11+0+5) defects / (3 units * 1000) * 1,000,000 = 5333.33
Active Job DPMO (IPC 7912)
| Filter supported: Operation Alias |
|---|
Calculates the defects per million opportunities, at the assembly level. IPC 7912 DPMO is (the total defects collected / (the unit count * the assembly opportunities)) * 1,000,000.
Example:
Unit 1: 11 defects
Unit 2: 26 defects
Unit 3: 5 defects
Opportunity count per unit is 2000.
DPMO is (11+26+5) defects / (3 units * 2000) * 1,000,000 = 7000
Active Batch Defects Per Unit (DPU)
| Filter supported: Operation Alias |
|---|
The DPU is the total defect count / the total unit count (configurable to use x number of the most recent units).
Example:
Unit 1: 11 defects
Unit 2: 26 defects
Unit 3: 5 defects
DPU is (11+26+5) defects / 3 units = 14
Pass Yield
| Filter supported: Operation Alias |
|---|
Configurable to use first pass, or second pass yield. Pass yield is calculated using pass unit failures. First pass failures are units that have ever failed and second pass failures are units that have ever been failed more than once. Pass yield is calculated as ((total units – total failed) / total units) * 100.
Example:
Unit 1: passed
Unit 2: failed then passed
Unit 3: failed twice
First Pass Yield is ((3 – (1 + 1) / 3) * 100 = 33.33%
Second Pass Yield is ((3 – 1) / 3) * 100 = 66.67%
Overall Equipment Effectiveness (OEE) overview
OEE = Availability x Performance x Quality
Where
Availability= Operating Time / Planned Production Time
Performance= Ideal Cycle Time / (Operating Time / Total Pieces)
Quality = Good Pieces / Total Pieces
The order of calculation is as follows:
Availability
Performance
Quality
- Availability is the percentage of the planned time that a machine is available. It is a measurement of uptime that is designed to remove the effects of scheduled downtime, quality and performance.
- Performance is the percentage of the designed speed at which the machine is running. It is a measurement of speed that is designed to remove the effects of availability and quality.
- Quality is the percentage of the planned total units produced. It is a measurement of yield that is designed to remove the effects of availability and performance.
Each of these calculations produces a value between zero and one. When this information is displayed, it is usual for this value to be multiplied by one hundred and presented as a percentage value.
Example:
Availability 0.56
Performance 0.78
Quality 0.87
To calculate OEE:
= 0.56 x 0.78 x 0.87
= 0.38
When displaying this information, the following would be displayed:
Availability 56%
Performance 78%
Quality 87%
OEE 38%
Overall Equipment Effectiveness (OEE)
| Filters supported: Operation Group Template, Operation Template, Operation Alias, Workstation |
|---|
The product of OEE Availability, OEE Performance and OEE Quality.
Example:
OEE =AvailabilityxPerformancexQuality
=0.75 x0.73 x0.33
=0.18
=18%
OEE Availability
| Filters supported: Operation Group Template, Operation Template, Operation Alias, Workstation |
|---|
This value reports the percentage of up-time achieved during planned production time during a specified time window. Planned production time is considered all time within the specified time window if zero planned production times have been defined. If one or more planned production times have been defined then the total planned production time is the time within the specified time window that has been explicitly identified as being production time.
Example:
A planned production window is defined from 8:00 am through 12 pm. If the specified time window for which OEE Availability is to be reported is 3 hours and the current time is 11:30 am, the planned production time is 3 hours as the time window for reporting extends from 8:30 am (11:30 am – 3 hours) through 11:30 am. However, if the time is 8:30 am, the planned production time would be 30 minutes as 5:30 am through 8:00 am was unplanned and only from 8:00 am through 8:30 am was planned.
Taking this a step further, if the machine was down from 8:00 am through 8:30 am, then when reporting OEE at:
8:30 am Planned Production Time = 30 minutes
Operating Time = 0 minutes
OEE Availability= (Operating Time / Planned Production Time)
= (0 / 30)
= 0 (0%)
11:30 am Planned Production Time = 180 minutes
Operating Time = 150 minutes
OEE Availability= (Operating Time / Planned Production Time) x 100
= (150 / 180) x 100
= 0.8333(83.33%)
Operating time is calculated by reviewing machine state information for the planned production time window and summing up the duration of each machine state which is designated as operating time. The designation of a machine state as operating time or not is achieved in the FactoryLogix Analytics iMonitor Settings area.
If no machine state information is recorded within the planned production time window the last known machine state value shall be used. If no machine state information has ever been recorded for the operation then the operating time shall equal the planned production time window.
In iMonitor you can determine Operating Time using reason code information instead of machine state information. A reason code is assigned to a machine state record by an operator. As a result, every time a new machine state is recorded, an operator must assign a reason code (through the UI) before that change in machine state can be used to determine operating time.
Consider a situation where a machine state is recorded and the operator assigns a reason code that isn't considered operating time. From the time associated with that machine state record forward no further changes in machine state have had a reason code assigned. All time from the last machine state record with a reason code forward will be treated as operating time—or not—depending on whether the reason code is considered operating time. Reason codes are historical by nature. We do not recommend using reason codes when creating dashboards to display OEE information.
For an Operation Group, the same calculation is used as for all Operations in the group, and the lowest Operation availability is returned.
Example:
If time frame is 1 hour
Machine 1: 15 minutes down = 45 minutes / 60 minutes = 0.75(75%)
Machine 2: no down time = 60 minutes / 60 minutes = 1.00(100%)
Machine 3: 20 minutes off = 40 minutes / 60 minutes = 0.67(67%)
Availability = Machine 3 (lowest availability) = 67%
OEE Performance
| Filters supported: Operation Group Template, Operation Template, Operation Alias, Workstation |
|---|
Performance is calculated as Ideal Cycle Time / (Operating Time / Total Pieces).
The Ideal Cycle Time for each process point is recorded in the iMonitor settings area of the Analytics client application and does not change unless modified by an operator.
Total Pieces is calculated by counting up the number of WIP transactions recorded during the planned production time, where planned production time is calculated as described above. If availability is an issue, it may be easier to get a high-performance figure because total pieces is determined across the whole planned production window, and not just the operating window. This is an integral part of OEE design which is designed to focus on availability in that situation.
Example:
If the Ideal Cycle Time for a given machine is 60 seconds and the Operating Time is 1 hour then at 100% performance, we would have to process the following number of items:
Performance= Ideal Cycle Time / (Operating Time / Total Pieces)
1 = 1 / ( 60/ Total Pieces)
Total Pieces= 60
If we had processed 48 items the performance would be:
Performance= Ideal Cycle Time / (Operating Time / Total Pieces)
= 1 / ( 60/ 48 )
= 0.8 (80%)
For a factory line, it is the same calculation as above for all process points in the factory line. The lowest process point availability is returned.
OEE Quality
| Filter supported: Operation Alias |
|---|
Looks at first pass yield achieved during planned production time during a specified time window.
Quality = (Total Pieces – Total Failed) / Total Pieces
Example:
Unit 1: passed
Unit 2: failed then passed
Unit 3: failed twice
Quality = (Total Pieces – Total Failed) / Total Pieces
= (3 – 2 ) / 3
= 0.33 (33.33%