Overall Equipment Effectiveness

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Before delving into detail about OEE it is worth having a basic understanding of one of the most striking characteristics of Adroit: the extensible object model at the heart of its SCADA server. The objects in the server are called agents in Adroit terminology, and range in type from simple Boolean, Integer, Real types, through conventional SCADA types like Digital, Analog, right up to rich data types that, on their own, implement complete sub-systems such as Alarm Management and Overall Equipment Effectiveness.

An Adroit agent or data type is implemented as an independent DLL that need only conform to a defined signature essentially a name format (t_xxx.DLL), plus a defined set of exported create, get, set, delete... functions (or methods). Internally each agent contains a number of properties which act as primitive storage slots that can be of type Boolean, Integer, Real, or String. The way these various data types are implemented is by creating different agent type DLLs that contain different compositions of slots. The data types exhibit different behaviours by having custom processing (overridden implementations) for the ‘get’ and ‘set’ methods on their different constituent slots.

The result has been that with successive versions of Adroit over the years, it has been possible to add new, rich data types to the Adroit SCADA server, and is primarily what we mean by describing the object model as being extensible.

The Overall Equipment Effectiveness agent is a prime example of this - a rich data type that has fairly recently come into being:

What is OEE
Overall Equipment Effectiveness (OEE) is a measure of how effectively an item of equipment, a group of equipment items, or even an entire plant or factory is being utilised.

Specifically, it is the percentage determined by the cumulative impact of the following three factors:

OEE% = Availability% x Performance% x Quality%

OEE in Adroit

This dialog or form, showing numerous OEE slots or properties, represents a single OEE agent instance in Adroit. A complete plant or section of plant will typically have several OEE agents – one for each equipment item, and possibly one the overall plant or plant section.
OEE Configuration Dialog
The advanced configuration dialog allows you to designate other Adroit tags as parameters in an OEE agent. Alternatively OEE parameters can be directly acquired from a PLC if they are available there.
Advanced Configuration Dialog

From the configuration dialogs you can see that an OEE agent may be used to measure a specific KPI, as well as calculate the OEE

KPIs are typically the variation of some production value over time, or of one production value versus another production value. Therefore an OEE agent can measure two variables:

If the 2nd value is not specified, then the 1st value is simply divided by time. In this way it is possible to measure production figures, such as ton/hr, kWh/ton, total produced, actual run-hours, etc.

By using OEE agents in tandem with instance(s) of another agent type Shift the measured KPI can either compare actual performance with benchmark figures or compare today’s performance with the previous day or the previous day's shifts.

Something else that can be seen on the advanced configuration dialog is a SQL connection string. This is used to specify a SQL database to which the various KPIs and OEE parameters are logged away for data warehousing purposes.