The evolution of user interfaces and HCI in process control environments
November 2007
By Hannu Paunonen, Jaakko Oksanen, Toni Koskinen and Mikko Kovalainen
Boosted by new technology and the increased level of automation, process control work has changed drastically over the past few decades. Today, the work is performed in quiet and office-like control rooms. Information from the process is transferred to the operators by the control system through its user interface. The high level of automation has changed the operation from driving the process to supervising it. The work has become more mediated and conceptual because there is no direct contact with the process, yet at the same time the control system creates an even more illustrative artificial picture of this process. Detaching the operator from the process has enhanced the development of organizations where operation, maintenance, and development tasks are merging together. Behind these changes are the continuous requirements of efficiency and flexibility coming from the tough competition on the market.
The development of process control systems reflects the special requirements of manufacturing. Demands for usability have always been very high and, based on that, special functions for monitoring the process and perceiving an extraordinary situation, for example, have been included in the user interfaces as standard in all fields of the process industry. Extensive research has been undertaken around decision-making in process control. In addition to this, especially during the past decade, process control systems have been affected by a general evolution of usability theory, organization theory, and the development of information systems and user interface technologies. These parallel threads of progress have focused on the specialist environment of process control work and have produced a special kind of development scenario. Tools for exchanging expertise and knowledge, for instance, have become integrated functions of control systems. Today, an expert in a remote location, fed with real-time information from the target plant, can cooperate and participate with his knowledge, skills, and experience in the decision-making process.
This development is now going to go a step further when new network-enabled cooperative forms, familiar mainly from people's private computer activities, come to the plant floor. A virtual network of experts will be built around production activities and will be supported by future process control systems.
The history of process control user interfaces
Very high usability is required from the user interfaces of process control systems. However, the large, complicated, and integrated process entities have led to a situation where nobody can control the process alone. Knowledge support from the systems and contacts with experts and the rest of the organization is needed. The development of computer-based process control user interfaces reflects both this increased demand and developments in information system technologies. The following steps and breakthroughs in user interfaces can be distinguished:
- Graphical, based on the structure of process equipment
- Task oriented, based on operator's tasks
- Knowledge intensive, containing supporting knowledge
- Collaborative, supporting collaboration.
The first modern digital control systems developed in the 1970s offered graphical user interfaces. They inherited their models of presenting information from conventional systems, which showed the process measurements as indicators in large wall panels arranged on top of graphical drawings of pipes and equipment. Displays on monitors caused problems for the operators because only part of the process was visible at any one time and the displays had to be continuously swapped around. Low-resolution monitors could only show a small number of measurement values in a picture. The problem was called 'keyhole effect'.
Step by step in the 1980s, the advantages of computerized user interface technology were realized and displays were designed taking the operators' tasks into account. The challenge was to consider what information should be presented in different tasks and how it should be presented. For example, trend curves showing measurement history have become a very effective way of illustrating the process dynamics for noticing changes and for understanding interdependencies. The display resolutions increased and more information could be included on screen. Based on windowing technology, information can be selected in a more flexible manner. There is less reliance on the operator's memory than before. The idea of swapping displays has been reassessed from simply being a nuisance to being a powerful tool for selecting relevant information. The first large overview screens were also put into use in control rooms.
In the 1980s, intelligent expert systems raised expectations. It was thought that control room equipment would include systems advising the operators in complicated situations. Today, neural networks, fuzzy controls, and knowledge-based systems have found their place in common automation functions, but intelligent operator support systems have not entered control rooms, with the exception of a few special applications. The reason behind the absence of such applications is the large amount of expert work needed in developing and maintaining them. However, supporting knowledge has entered the process control field since the mid-1990s as simple text applications. Their implementation and updating is integrated into the regular processes and tools in the engineering applications for control systems. The basic principle of these text support systems is that by pointing at a process object on a display, the operator retrieves associated design knowledge and information about the pointed object. The system offers the operator knowledge and help, but does not make decisions for him or her.
Today's control systems and networks have also started to support collaboration within organizations. Modern networking technology and standardization have opened up possibilities for transferring and displaying information wherever it may be needed. The tools supporting the exchange of information and knowledge are, for example, electronic diaries and remote support connections. Electronic diaries are used as discussion and information exchange tools for organizations, and they have clearly changed the working habits where they have been introduced. They also collect and store the organization's experiences, which can be used for decision support purposes to solve similar situations at a later date. Suppliers of process equipment and automation provide production plants with remote services for supervising, reporting, and managing problematic situations. Through the networks, the remote expert center is connected to several plants and the remote experts see the same information as the operators in the local control rooms. Whenever necessary, the expert center contacts the plant or vice versa.
The future – collaborative interaction in process control
As the contemporary working environment requires the people carrying out the process control to have a lot of skills and knowledge, interaction between the human actors gains increasing importance in this context. The interaction between the human actors happens more often through the supporting and integrated information and communication technology (ICT) that provides the communication channels. Examples of these channels on different time frames are bulletin boards, emails, instant messaging ('chatting') and video-conferencing. What the system can do is offer the tools, associate the communication to the context, and increase its efficiency with intelligence. As a result, system-based tools can automatically integrate the current process values with historical process trends, aligned with descriptions of human activity such as electronic diary entries. These data can then be further elaborated in the communication between the local and remote experts performing process control and management.
The current trend in the operation and management of different types of process plants is the breakdown of the whole organization into smaller and very specialized organizational units. These units perform their own part in the overall process and aim to provide the best possible effectiveness, efficiency, benefit and utility according to the goals set by the main contractor. For instance, ownership, operation and maintenance appear as separate functions that may be contracted individually by the owner of the process plant through the purchase of a specific service from an external service company. In these types of organizationally networked environments success depends not only on flexible and switchable interfaces, but also the ability of different business stakeholders to collaborate and cooperate through technology.
The application of the transaction cost theory to computer-mediated collaboration also highlights the need and the option to analyze the value of business transactions that are mediated by ICT. From this standpoint, interaction in process control appears to become deeply integrated into business arrangements and should be modeled as such. The communication mechanisms that take place through HCIs create part of the business value. Examples of new technical ways of providing flexible business links are, for instance, instant messaging or bulletin board systems between closely connected business partners that may even require situation awareness.
However, interaction in process control is not only concerned with business value. The interactive environment in which humans act has a significant influence on their daily activities. The design of all new user interfaces should be considered from this standpoint. Despite the 'serious' nature of process control throughout its existence, the evolution of technological, business, and societal surroundings also has an effect on HCI development in process control. As an example, it could be useful to adopt the instant messaging culture from private, leisure applications to process control environments, where long distances and shift work are obstacles for communication. Building an ad hoc virtual team composed of local and remote experts to solve a problem at hand could also be supported by the system. Can computer games bring something new to the teaching of process control?
The support for collaborative interaction and the value-centered approach to process control extends the application area of HCI to a level that should be further elaborated upon. We need more research, better conceptual understanding, and modeling of the characteristics of these new areas that provide support for the creation of innovative systems, tools, and services for the field of process control. We are likely to see the emergence of new interesting research questions that address topics such as equality, culture-(in)dependency, or even 'entertainability' in process control interfaces.
Conclusions
Human interfaces in process control are more and more becoming collaboration environments in which the different stakeholders, including loosely connected external participants of the process control community, interact with the technical and social system. Part of this interaction is conducted in a formal and predetermined way, but as the requirements for dealing with more dynamic and abstract issues in the various process control situations increase, 'non-formal' ways of interaction with and through process control systems also become more important. This development points to the need for improved models of interactivity in process control.
Flexibility in a dynamically changing business environment has been, and will be, a major requirement for process control. There are always discussions about the need for changes in technical systems that are initiated by the changes in the operative surroundings of process control systems. This sets out a general requirement for the design and development of flexibility within the systems themselves. We can even go one step further and start modeling the information and communication systems as an enabling platform that facilitates and fosters change instead of merely being an object that needs to be changed. Design for flexibility, both in terms of technical components as well as in terms of human participants will require additional emphasis in the future. Enabling possibilities for different arrangements in the division of work in systems, securing the participation of ad-hoc stakeholders in the process, as well as the integration of dynamically changing service providers, appears to a be a challenging modeling and implementation task for researchers and practitioners in the future for process control – including the HCI field.
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A community is a group of people sharing the same goal. In our industry – operators, maintenance staff, process developers and paper mills – all share the same goal: production results.
Communities are THE way of working in the Internet world of today. Now the same is happening in manufacturing industries. The story of the Linux operating system – the brainchild of Linus Torvalds – is well known. And when the computing community took the system as its own, it became a world-class operating system, developed by a community of people sharing information.
How do communities work? An organization works together toward to the same results – targeted quality, maximum production, minimum environmental emissions and costs. As with the worldwide web, all data are available to all users, regardless the physical location and time of day. Staff can access the community whenever they want and discuss problems within discussion forums that contain a record of all production events. And when there is a need to communicate with other parts of the community, the user can do it with one click.
Results are achieved through people interacting and basic systems collaboration. Discussions, for example, are a basis for continuous learning and innovation. When something new is found in the system, it is sent to everyone involved. The concept of 'community' includes the freedom to present ideas. Based on these, innovative approaches can be found and implemented. The most competitive mills are today seeking this kind of culture and the most advanced ones already have it.
The production community includes not only the mill's own staff but also other production plants. Many corporations already have expert centers or task teams to help individual plants. Communication happens online via video negotiations, bulletin boards and discussion forums directly connected to the control room. More and more online and wireless communication methods are used in the industry. Process and automation suppliers are also part of the community. Their machinery and process knowledge is used daily as part of normal operations.
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