Changing Rooms

Article by Andy Brazier AMIChemE

Best practice on specifying, designing, commissioning and operating control rooms

STANDARDS and guidance relating to control rooms have been available for many years but the reality is that it is widely accepted that control room design is often poor. Often the design is left to engineers who either do not recognise the importance of human factors, or perceive the available guidance to be inappropriate for ‘real life’ application.

If you have been tasked with designing a new control room or making significant modifications to an existing one, where would you even start? So many questions – from colour schemes to fish tanks to display and monitor settings and more besides.
If this is you, then worry not, help is at hand, in the form of a new edition of EEMUA 201 (3rd Edition, Control Rooms: A Guide to their Specification, Design, Commission and Operation), which was published earlier this year.

Rather than a simple update, the opportunity has been taken to develop a complete guide to designing and evaluating all aspects of new and existing control rooms and associated human machine interfaces (HMIs).

What’s new?

In an ideal world every control room design team would have access to competent human factors support. In the real world this is not always practical or possible. The guide aims to direct designers to recognise the human factors and actively involve control room operators (CROs) in the process.
EEMUA 201 covers a very important subject. The role of the CRO in managing risks of modern process plant is indisputable. Detecting deviations early, diagnosing the causes reliably and responding promptly and appropriately all contribute to the avoidance of major accidents and reduce reliance on automated systems. To do this, CROs need to be healthy and alert, all of the time. The design of the control room and HMI are significant human performance influencing factors.

A key aim with this update has been to put a stronger focus on human factors throughout. Design is a compromise. There is no single correct solution and often theory does not match practical experience. The guide highlights the decisions that need to be made, and gives information that can be used to achieve an optimum solution. The guide has been updated with input from a wide range of people with an interest in control room design, with a significant input from current CROs who are particularly important as they have to use whatever the designers come up with.

Questions answered

The updated guide sets out to answer a number of questions that are often asked about control room design, where the clear and practical answers have not always been easy to find. For example:

  • Can we use colour on graphics? ‘Grey screens’ have become common (with colour only used for critical information and alarms) but are unpopular with CROs. The guide states that colour can be used to show routine status of valves and equipment as long as it does not detract from critical information. Bright colours should be reserved for alarms but less saturated colours can be used for other information. The colour scheme must be fully documented and applied consistently on every graphic.
  • How many screens should we provide? When asked how many screens they want, CROs will inevitably answer “more”. But there are practical limitations on how many screens can be used at any time and often the problem is poorly-designed graphics. The guide states that four screens should be sufficient for the control system HMI. Others may be provided but should be considered as secondary to be used by the CRO for monitoring only and available for others to use.
  • Can we stack screens to form two rows? Ergonomic guidance shows that screens at eye-level cause less strain on the neck and so there are risks if the CRO has to look up to see screens at a higher level. But CROs are generally happy with stacked screens and point out that they only use the higher-level screens for monitoring, which means they do not look up for very long because short glances are enough. The guide states that two rows of screens is allowable and often preferred because it gives CROs better visibility of the information they need, with little risk.
  • Where do we put our large screens? Most modern control rooms will include one or more large screens but their purpose and use often has not been properly considered. In some cases the overall design of the control room has been compromised by locating them in a prominent, primary position. Large screens are used mainly for monitoring or as a focus for teams handling abnormal operations including emergencies. The guide states that large screens can normally be put in secondary locations, often to the side of the control console.
  • How bright should the lights be? Feedback from CROs shows that there is no ideal level of illuminance. It is a very personal issue, partly affected by age, and depends on the activity being performed, which can change continuously. The guide states that background lighting should be similar to the background of the screens used by CROs and that task lighting should be adjustable by each CRO to suit their activities and preferences.
  • Should there be windows? The trend over recent years has been to avoid windows in control rooms due to safety concerns, particularly resilience to explosions. This is very unpopular with CROs who feel isolated as a result. The guide states that windows should be provided wherever reasonably practicable and this requirement should be considered when locating the control building and orientating the control room.
  • How big should the control room be? Previous guidance has tended to suggest a footprint per CRO. Whilst this has been reasonable for larger control rooms it has not worked for smaller ones. The guide states that the minimum size is 30 m2 (ie for one CRO work position) and 45 m2 for two.
  • How high should the ceiling be? 3 m has been specified in the past as the minimum clear height but a lot of control rooms have lower ceilings. This affects perceptions of the room and makes it more difficult to incorporate effective lighting and ventilation and to arrange large screens for viewing. The guide states that 3 m should be considered as the minimum wherever reasonably practicable.
  • Should adjustable height desks be provided? Desks are available that can be adjusted, (including some sit-stand desks). Some people suggest these are required but CROs do not seem to share this opinion. The guide states that the desks and chairs provided should accommodate the CRO population, taking into account their height, but there is no reason to think that adjustable desks are necessarily required.
  • Should fish tanks be provided? This was a trend a while ago, with designers suggesting they had a calming or humanising effect. However, CROs feel they have little benefit and just give them more work to do. The guide states that any humanising features (eg fish tanks, pictures on the wall) should be selected by the CROs and not imposed by others.
  • What colour should the walls be? Pale or earth tone colours are generally best for the walls but can be uninspiring. The guide states that more interesting colours and textures can be used to create some interest but should not be in the direct view of the CRO when working at the console. The ceiling should be a lighter colour and floors darker.
Please Sir, I want some more: But there are practical limitations on how many screens can be used at any time

Changing tech

One of the challenges when updating a guide on control room design is that technology is changing so rapidly. This presents great opportunities but also risks. The guide includes some high-level information about some of these emerging issues to raise awareness and to prompt people to check the latest good practices. For example, technology that allows access to control system data and controls from outside of the control room is already available and becoming more prevalent. People accessing data from their desktop computer, tablet or mobile phone can enhance teamwork and data analysis but can cause confusion about who is in control and who responds if things go wrong. Also, it is one of many potential security issues. Security threats are continually evolving and new solutions are being developed in an attempt to catch up. The guide highlights that issues such as remote access and security need to be recognised very early so that developing solutions is an integral part of the design, and not handled as an add on at a later date. A security risk assessment should be a key activity to determine the level of threat and vulnerability of the systems being used.

Practical support

EEMUA 201 is not a standard and is not intended to replace any. Its role is to provide guidance on how compliance can be achieved as part of a wider context of striving to provide the best control room possible to the CRO end users.

The guide aims to provide practical support to anyone with responsibility for control room design. If you are designing a new control room or making significant modifications to an existing one the guide includes a template for a human factors integration plan (HFIP).

This is a powerful tool for identifying the potential human factors issues and opportunities at an early stage in the project and for managing implementation of appropriate solutions to achieve an optimal design. The template includes a mixture of standard text for you to adapt to your project and prompts for when you need to delve deeper or obtain specialist support. A key message is that you want to start generating a HFIP as soon as possible in a project, and plan to review it and keep up to date throughout.

If you have been given the job of reviewing a control room design, whether this is for a new project or an existing control room, the guide provides a comprehensive checklist that will guide you through all the important issues to consider, and directs you to the sections in the guide which will help you make your evaluation.

It is not simply a tick-box exercise because every control room is unique. Instead it assists you in deciding if design is optimised and to determine if the inherent risks are being managed effectively. Clearly there are far more existing control rooms than there will be new projects at any time.

Using the checklist provides you with a basis for a gap analysis that you can use to decide if risks are as low as reasonably practicable (ALARP) and to prioritise any actions for improvement.

Article by Andy Brazier AMIChemE

Associate Consultant, Wilde Analysis

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