Toolkit mental workload

Background information of the tools

To get a grip on mental workload, Intergo has a toolkit of tested instruments. All our instruments are diagnostic: the results tell you what needs to be dealt with.

Experienced Workload: Integrated Workload Scale (IWS)

IWS (Integrated Workload Scale) is an instrument developed by the University of Nottingham. Intergo translated the tool for the Dutch situation and extended the model with a standardisation, guide and scoring methods. With IWS the experienced workload and the activities performed are registered every five minutes.

Task Demands: Task Weighing, OWAT and Bobit

Task Weighing, OWAT and Bobit are instruments to measure the task demands. They are easily applicable for the prediction of workload in new working situations, for example for new functions, but also for working with new systems or with new strategies. With the predicted mental workload it is possible to optimize the work strategies, to better divide work over functions and to search for better aids.

Task Weighing

Task Weighing is especially developed with and for train dispatchers. Task Weighing makes a calculation of the ‘task’ demands’ in which both the cognitive and physical activities are represented. Also, other influences are considered like puzzling, keeping the overview etc.


The OWAT instrument is similar to Task Weighing, except that OWAT can be applied in any control room with process control and similar tasks.

Task Weighing and OWAT are developed by Intergo and is validated extendedly. They are a unique set of instruments in the Netherlands.


Bobit is a simple and universal applicable workload instrument. It is based on the amount of time spend on a task or activity and takes to a limited extend into account the kind of task and the way someone performs a task.

Work environment: ATMOS

ATMOS is an instrument that zooms in on the aspects that are important in your organization. It consists of a short questionnaire, which can be implement in your current employee satisfaction survey. De questionnaire has a function to identify difficulties in your organization. These points are further discussed in a meeting with management and employees.

Of course, we can also help you with the implementation. Solutions or (re-) designs are usually first tested or tried out in a small setting. Last but not least, we evaluate the adjustments.

Use of our tools

Which instrument to apply depends on the questions and problems that occur in the organisation. An existing situation with a high mental workload needs a different approach and different instruments than a new situation. Also the history with mental workload in a function is important to decide which instruments are suitable to give an objective answer.

Together with the client we decide which instruments to use. Our workload model is the basis for this conversation. We have the experience that it leads to the best results when we use the instruments for task demands, work environment and work experience simultaneously. This also gives the opportunity to connect the different aspects of workload.