Whiteboard Metrics Calculations - Machine Level Hourly View

The purpose of this article is to explain how to calculate and describe the significance of values in the Machine Level - Hourly View on the Whiteboard.

Table of contents

OEE Metrics Calculations

• OEE = Availability * Performance * Quality

  • Availability = Uptime / Planned Productive Time

  • Performance = (Number of parts produced) / (Machine rate * Uptime)

  • Quality = [(Number of parts produced) - (Number of parts rejected)] / (Number of parts produced)

• OEE = Availability * Performance * Quality Ratio

• OEE = Good Production (pcs) / ( Expected speed (parts/hr) * Scheduled Time (hr) )

Examples

Example 1: All grey period (idle status)

In this case, the machine has a 1-hour unscheduled period (from 23:30 to 00:30) shown in grey - where does the number “189” come from?

This is the Expected Production (Parts), which represents the number of parts that could have been produced if the machine was running. It is calculated as follows:

Expected Production (Parts) = Runspeed (Parts/Minute) * Duration (Minutes)

Furthermore, the job details can be found through the job list view or just by clicking on the job column on the current page. A pop-up window similar to the one below should show up.

Next, substitute the specified number (e.g. Runspeed) into the equation.

Expected Production (Parts) = Runspeed (Parts/Minute) * Duration (Minutes)

189 (no decimals showing up by default) = 3.158 (parts/min) * 1 (hr) * 60 (min/hr)

Example 2: Mixed uptime and downtime periods

In this example, you can see multiple machine statuses in the first hour. Similar to example 1, Runspeed (Parts/Minute) can be found in the Job pop-up window. The value is 3.158 in this case.

The following table shows how items in the quick view are calculated:

Quick View	Machine Status	Key Numbers (Parts)	Duration	Equation	Math Calculation	Description
	Uptime	97	30.1 mins	Uptime parts = Runspeed (Parts/mins) * Uptime Duration (mins)+ Running Type (Gain) - Scrap Parts	97 = 3.158 * 30.1 + 3 -1	Produce 97 parts in running state/uptime. No downtime issues happening in this duration
	Downtime	76	24 mins	Downtime parts = Runspeed (Parts/mins) * Downtime Duration (mins)	76 = 3.158 * 24	It should have produced 76 parts but failed. Micro-stoppage and idle status are triggered in this period
	Unscheduled	18	5.9 mins	Unscheduled parts = Runspeed (Parts/mins) * Unscheduled Duration (mins)	18 = 3.158 * 5.9	Unscheduled production values (18 parts)
	Opportunity	77	24.3 mins	Potential parts = Runspeed (Parts/mins) * Opportunity Duration (mins)	77 = 3.158 * 24.3	It shows the extra capacity (77 parts) which can be considered to maximize the total production
	Scrap	1	18 sec	Scrap values added manually	N/A	Bad parts, reported by customers

The following table shows how the values in the OEE gauge and the Cycle Gauge are calculated.

Gauge Type	Quick view	Description
OEE		Numerator = Good Production = Uptime parts = Runspeed (Parts/mins) * Uptime Duration (mins)+ Running Type (Gain) - Scrap Parts 97 = 3.158 * 30.1 + 3 -1 Denominator = Expected Goal = Uptime Parts + Opportunity Parts - Running Type (Gain) 171 = 97 + 77 - 3 OEE = Good Production / Expected Goal 57% = 97 / 171
Cycle		Numerator = Production time = Uptime Duration / Uptime Parts * 60 (Unit conversion) 18.5 = 30.1 / 97 * 60 Denominator = Scheduled Cycle time Cycle time = 18.999 = 19.0 s (See job window) Variance = 18.5s - 19.0s = -0.5s

Example 3: Production without Jobs

If a machine is not running on a job, the way calculations are done changes. In this case, the Machine Rate (prod/min) can be found in the PEConfig settings. For this example, the Machine Rate (prod/min) = 180

Quick View	Machine Status	Key Numbers (Parts)	Duration	Equation	Math Calculation	Description
	Uptime	5632	55.7 mins	Uptime parts = (Machine rate * Uptime) - Running Type (Loss)	5632 = 180 * 55.7 - 4387	Produce 5632 parts in running state/uptime.
	Downtime	781	4.3 mins	Downtime parts = Machine rate * Downtime Duration	781 = 180 * 4.3	It should have produced 781 parts but failed. Idle status are triggered in this period.
	Opportunity	781	4.3 mins	Potential parts = Machine rate * Opportunity Duration	781 = 180 * 4.3	Opportunity production values (781).

Gauge Type	Quick view	Description
OEE		Numerator = Good Production = Uptime parts = (Machine Rate * Uptime) - Running Type (Loss) 5632 = 180 * 55.7 - 4387 Denominator = Expected Goal = Machine rate * Planned Productive Time 10800 = 180 * 60 OEE = Good Production / Expected Goal 52% = 5632 / 10800
Availability		Availability = Uptime / Planned Productive Time Uptime = 55.7 = 56 mins Planned Productive Time = 1 hr = 60 mins 93% = 56 / 60
Performance		Performance = ( # of parts produced) / (Machine Rate * Uptime) # of parts produced = Uptime production = (Machine Rate * Uptime) - Running Type (Loss) 5632 = 180 * 55.7 - 4387 Machine Rate * Uptime = 180 * 55.7 = 10019 56% = 5632 / 10019
Quality Ratio		Quality Ratio = [(Number of parts produced) - (Number of parts rejected)] / (Number of parts produced) # of parts produced = Uptime production = (Machine Rate * Uptime) - Running Type (Loss) 5632 = 180 * 55.7 - 4387 Number of parts rejected = Scrap = 0 100% = 5623 / 5623

Briefly, in OEE gauge, Expected Goal can be concluded as below:

Expected Goal = Running + Opportunity + Running (Type)

Please note that for Running (Type), if it gains parts, Expected Goal=Running + Opportunity - Running (Gain). Otherwise, Expected Goal=Running + Opportunity +Running (Loss).

In addition to Running (Type), some cases include other components such as Production During Errors, Blocked Parts, Starved Parts, etc. We should add them to the equation as well. See Example 4.

Example 4: Production with complicated machine status

In this case, we have multiple machine status.

Apparently, the calculation formulas are the same as in the previous examples. But due to different machine types, the Expected Goal ( denominator of the gauge) is the most confusing part. Let’s look into it.

Starting from the basic equation in Example 3, we can expand it by adding some specific terms as below:

Expected Goal = Running +Opportunity + Running (Type) + Production During Errors + Blocked Parts + Starved Parts

360 000 = 103 109 + 127 744 + 128 967 + 11 + 35 + 54 + 25 + 43 + 12

With the addition now of faults and Late Start (which would also include Early Departure and Break Creep) we can simplify the equation to the following:

Example 5: Special case with small error

According to our equation, Running + Opportunity + Running (Type)=Expected Goal

494 314 + 599 020 + 45 958 = 1139 292

But in this case, 1139 309 – 1139 292 = 17. Where did we gain 17 parts?

You can see a setup gain of +16 on the 10th line down that accounts for missing parts.

Yes, there is an error here in 1 part; a 0.00009% error is acceptable.

There is production hidden under Test Run that does not show up in the Goal Column.