Category CONTROL ROOM DESIGN AND ERGONOMICS

Goal Analysis: An Example

The importance of formulating the goals in as concrete a form as possible has already been emphasised. Analysis of the system’s goals can best be done under the follow­ing three headings:

1. System Task

2. Criteria

3. Limitations

The task of a system may be to convert raw oil into various petrochemical products. It may also be to convert potential energy in the form of a stored mass of water into kinetic energy, and then to electrical power. A number of criteria apply to this task, for example, those of an economic nature. From the ergonomic viewpoint, the important criteria are to create a safe environment for the people in the production process and for those in the community...

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Systems Analysis

The traditional process is spread over several stages, is ineffective, and often gives poor results (see Figure 13.1b). This construction design is sometimes referred to as the ‘relay race’ model, referring to the stages that are as sequential as the passing of the baton in a relay race. One alternative is the ‘rugby scrum’ approach, where the expert teams collaborate to execute several stages in parallel, as shown in Fig­ure 13.1b. We first present an overview of Figure 13.1b, and then describe each of its subelements in more detail. Figure 13.1b should be regarded first as a philosophy of work; it cannot be treated as a concrete and general work model that can be applied directly to different circumstances.

The goal of a project is defined in accordance with traditional practice...

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DESIGNING NEW SYSTEMS

13.2.1 The Traditional Approach

When designing new systems, factories, and products, it is usual to follow the pro­cedure shown in Figure 13.1(a). The designers usually first determine the aim or goal of the system and then decide its technical design. This process is often done in several stages. The overall principal design comes first, followed by a more detailed technical design process. This process produces finished drawings and specifica­tions. Construction can then get under way. Usually during the construction stage, the organisation begins to seek new staff, conducts recruitment activities, and hires new staff as appropriate. Existing staff may also be retrained where staff relocation or transfer to a new system is involved.

Problems occur most often when personnel begin to use...

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An Overview

Toni Ivergard and Brian Hunt

13.1 Introduction…………………………………………………………………………………………….. 327

13.2 Designing New Systems…………………………………………………………………………… 328

13.2.1 The Traditional Approach………………………………………………………… 328

13.2.2 Systems Analysis……………………………………………………………………… 328

13.2.3 Goal Analysis: An Example…………………………………………………….. 331

13.2.4 Function Analysis…………………………………………………………………….. 331

13.2.5 Allocation of Functions……………………………………………………………. 332

13.3 Holistic View of Planning………………………………………………………………………… 335

13.4 Organisation of the Design Process…………………………………………………………. 336

13.5 Job Organisation and Alternative Forms of Automation………………………… 338

References and Further Reading……………………………………………………………………….. 341

13.1 INTRODUCTION

In this section we first consider the development of computerised process contro...

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RESEARCH NEEDS

One thread of current activities to be intensified in the future is following the objec­tive of predicting and controlling paper properties based on process variables. All approaches are generally data based. Specific outcomes currently available are sev­eral soft sensors and model-based control loops operated in paper mills as described earlier. These projects accumulate complex knowledge about the way in which the process has an impact on product quality. To date these projects are individual approaches. An overview and a holistic scientific approach are still missing, these being future tasks for research.

A second thread is dealing with the calculation of paper properties based on the properties of the components defined by the recipe, such as pulp, fillers, and chemical additives...

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HUMAN SOFTWARE AND MACHINE INTERACTION NEEDS

The new functions will be implemented on a larger scale successively after extensive testing at different sites. A common issue for success is that the operators understand and accept the functions. This means that the functions must be robust and reliable, and tuning and maintenance also must be easy to do by the operator themselves, automated, or applied from remote by experts from the supplier, or a combination of these in a structured, well-defined way.

To make the functions understandable they need to be explained in a visual way with intuitive graphics and text support. How to do this is a key task for success. Researchers at universities, in industry, and at the suppliers have to cooperate in dif­ferent ways by developing ideas and then test how these are accepted by the opera­tors...

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Online Use of Simulation and Simulation-Based Optimisation

Due to the complexity of the pulping process and the dynamics of the paper pro­duction process, process control systems have widely been established in the pulp and paper industry. For a typical application the number of the input/output (I/O) connections can vary between 30,000 and more than 100,000. In most cases con­ventional control technology is used. Operators see the actual values displayed on process displays, proportional, integrational, differential (PID)-controllers help to operate the plant.

Various approaches can be followed to manage these complex systems in an optimal way. The first issue to be addressed is how to handle the huge amount of data available within the system...

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Off-LiNE Use of Simulation and Simulation-Based Optimisation

Perhaps the most typical applications of off-line simulation in pulp and paper pro­duction processes are various design problems starting from defining elementary mass and energy balances for a process concept with steady-state simulation to using dynamic simulation to integrated design of process and control (Kokko, 2002). As the design task progresses, the model fidelity increases but the scope of simulation often decreases from plant-wide models to subprocesses or individual unit opera­tions. Unit operation development is often supplemented by model development. In this application, models are not necessarily used for getting quantitative results but rather for increasing knowledge on the underlying phenomena behind the unit opera­tion...

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Modelling and Simulation Software

For modelling and simulation purposes there are numerous software packages cur­rently in use in the pulp and paper industry. In general terms, it is possible to subdi­vide them into three groups: [22]

and thus providing the full functionality and at the same time safeguarding the undisclosed code (Maybock, 2004). In line with this, big equipment suppliers like Andritz and Metso have bought companies that develop flow­sheet-oriented software. Now, only a few software suppliers are indepen­dently active on the market.

• Software for data analysis and data-based modelling and simulation— This type of software is typically applied in cases where no physical models are available or even the question of cause and effect is unresolved...

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Availability of Data as an Important Success Factor

The availability of data is an important success factor for any modelling and simula­tion project. Nowadays mills have access to extensive process data. While there have been high levels of investment to install and operate databases, data management software, and process monitoring systems, the value currently derived from these sys­tems tends to be low. This puts pressure on the promoters of the investment and their common belief that this high amount of data will be a value in itself. In many cases this proves to be wrong. Typical reasons besides a lack of expertise to properly anal­yse data are that parts of the process are not available to the database system or that the process is not equipped with some perceived need to solve a specific technological question...

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