1
1
Introduction, How HMI
Has Been Evolving
I. Nimmo
User Centered Design Services
This section gives a short introduction on how human–machine interfaces ( HMI) have
evolved: from analogue instruments ( such as gauges) local to the plant equipment to
centralized computer-based control systems enabling control of complex operations.
Knowledge of how to provide a p erformance-based design between the human operator and the computer system is required to reduce the risk of accidents. At the end of
this chapter, a few suggestions on good practices related to HMI design and how to
deliver a good Return On Investment ( ROI) from an HMI upgrade are provided.
IN THE BEGINNING, HMI EVOLVED AS
TECHNOLOGY BECAME AVAILABLE
HMI have been evolving for the last 50 years. In the early days of instrumentation,
the HMI was local to the instrument, for example, a pressure gauge, a temperature
bulb, a level indicator. As instrument signals extended over greater distances to
the local control room, local control room indications were provided and collected
together onto an instrument panel. These were still gauges, but some were collected
into charts. Some signals now provided process values ( PVs) to pneumatic controllers and resulted in PID ( proportional– integral–derivative) control of valves and
other devices (Figure 1.1).
A PID controller is a control loop using feedback that is widely used in industrial
control systems. A PID controller continuously calculates a deviation as the difference between the desired setpoint and a measured process variable and applies an
error correction based on proportional, integral, and derivative algorithms.
CONTENTS
In the Beginning, HMI Evolved as Technology Became Available
1
...........................
First, Computer Interfaces Were Mere Copies of the Hardware Solutions
2
................
No Human Factors or Ergonomics Were Considerations in the Design
2
....................
Lack of Philosophy and Style Guides
6
........................................................................
The Lack of a Hierarchy Required Many Screens to Provide an Overview
7
..............
The Power of the Computer Allows an Increase in Scope of Control
8
.......................
Control Rooms and SA Have Not Necessarily Evolved with the New HMI
9
.............
Current Good Practices for Designing HMI
11
............................................................
References
11
................................................................................................................
1
Introduction, How HMI
Has Been Evolving
I. Nimmo
User Centered Design Services
This section gives a short introduction on how human–machine interfaces ( HMI) have
evolved: from analogue instruments ( such as gauges) local to the plant equipment to
centralized computer-based control systems enabling control of complex operations.
Knowledge of how to provide a p erformance-based design between the human operator and the computer system is required to reduce the risk of accidents. At the end of
this chapter, a few suggestions on good practices related to HMI design and how to
deliver a good Return On Investment ( ROI) from an HMI upgrade are provided.
IN THE BEGINNING, HMI EVOLVED AS
TECHNOLOGY BECAME AVAILABLE
HMI have been evolving for the last 50 years. In the early days of instrumentation,
the HMI was local to the instrument, for example, a pressure gauge, a temperature
bulb, a level indicator. As instrument signals extended over greater distances to
the local control room, local control room indications were provided and collected
together onto an instrument panel. These were still gauges, but some were collected
into charts. Some signals now provided process values ( PVs) to pneumatic controllers and resulted in PID ( proportional– integral–derivative) control of valves and
other devices (Figure 1.1).
A PID controller is a control loop using feedback that is widely used in industrial
control systems. A PID controller continuously calculates a deviation as the difference between the desired setpoint and a measured process variable and applies an
error correction based on proportional, integral, and derivative algorithms.
CONTENTS
In the Beginning, HMI Evolved as Technology Became Available
1
...........................
First, Computer Interfaces Were Mere Copies of the Hardware Solutions
2
................
No Human Factors or Ergonomics Were Considerations in the Design
2
....................
Lack of Philosophy and Style Guides
6
........................................................................
The Lack of a Hierarchy Required Many Screens to Provide an Overview
7
..............
The Power of the Computer Allows an Increase in Scope of Control
8
.......................
Control Rooms and SA Have Not Necessarily Evolved with the New HMI
9
.............
Current Good Practices for Designing HMI
11
............................................................
References
11
................................................................................................................