MIT AATT Model Project

PUMA (DRA)

Note: To be revised soon.

(08/07/96 KK)

1. Primary Model Category

Human Factors: workload modeling.

2. Summary

PUMA is a method and toolset for the modelling, in fine detail, of human workload. It was developed for NATS to help them in their work on future upgrades to NERC (New En Route Centre, the en route air traffic control centre for the London FIR). PUMA allows expressing controller tasks, defining a scenario of aircraft movements, and calculating the workload that results as the scenario plays through and the tasks are executed (and then altering tasks, repeating the calculation, and seeing the changes in workload). It uses the Wickens Multiple Resource Theory approach to calculate workload, and expresses this as a graph of workload against time.

3. Input Requirements

Required tasks; Air traffic scenarios; other data files; video recordings etc..

4. Outputs

Graph of workload against time.

5. Major Assumptions

Unknown

6. Computational Characteristics

PUMA is built on top of a proprietary object-oriented modelling environment (Lisp-based) and runs on Unix workstations and Mac workstations.

7. Modularity and Flexibility

Unknown

8. Status

The latest version is 2.2b. Roke Manor Research licences the system to third parties, as a fully supported product as well as supporting NATS's use.

9. Extent of Model Verification

Unknown

10. Principal Applications

PUMA has been used for UK ATC studies, and also under contract to Lfv (the Swedish CAA) to analyse the complete Swedish ATC system (tower, TMA and en route), and licences have been taken by Spain (AENA, the Spanish CAA), and Eurocontrol.

AENA (The spanish CAA) has been working with RAMS for enroute studies. For workload analysis purposes, PUMA was hooked to RAMS the following way: RAMS was run normally. Each time a controller activity is generated in RAMS, it is sent to PUMA as a PUMA event. RAMS was suitably modified to detect task triggers.

PUMA has also been used for non-ATC purposes. In principle it's applicable in any area where tasks can be well defined, and the resulting workload needs to be determined.

11. Availability

Roke Manor Research (a contract R&D company, part of the Siemens organisation) developed PUMA for NATS during 1993, and have been developing it for them under contract since. The latest version is 2.2b. Roke Manor Research licences the system to third parties, as a fully supported product.

12. Information for Model Evaluation

13. Summary Evaluation

PUMA is a method and toolset for finely detailed modelling of human workload. It was developed for NATS for their work on future upgrades to NERC (New En Route Centre, the en route air traffic control centre for the London FIR). NERC will have its capacity enhanced by the provision of computerised support tools for the controllers, and NATS needed a desktop system to evaluate and filter out ideas, in terms of their effect on controller workload.

PUMA is a means of expressing controller tasks, defining a scenario of aircraft movements, and calculating the workload that results as the scenario plays through and the tasks are executed (and then altering tasks, repeating the calculation, and seeing the changes in workload). It uses the Wickens Multiple Resource Theory approach to calculate workload, and expresses this as a graph of workload against time.

PUMA is a suite of integrated tools, supporting a range of functions including task analysis (including the analysis of video recordings - it has a fully integrated video analysis system), task synthesis, scenario definition, task sequence definition, and workload calculation.

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