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HMI Measures for Improved Sensemaking
one the DPOs need to make a correct assessment of the situation and to best evaluate
the effect of any countermeasures that are being made. It could be that the current
user has actively organized the screens to best fit the planned situation ( and thus not
necessarily for the developing o ff-normal situation) or that the previous user has
arranged the screens to fit his or hers personal preferences which may not entirely
serve the current user and situation. But since the screens can be re-configured at any
time by the users, why is this a problem? Why cannot the DPOs simply reorganize
their screens to best fit changing circumstances?
When the nuclear industry began digitalizing powerplant control rooms, similar
issues were raised. In the old, analogue control rooms, every process function and
every component had its own dedicated, analogue control mechanism, located at
a fixed position in the room ( so-called “ spatially dedicated” interfaces). The new
screen-based control systems on the other hand were highly flexible ( user configurable), and the users could bring up any component or any piece of information on
any screen. By system developers this was considered an advantage: more compact
control environments could be made, more powerful information graphics could be
designed, control functions could be organized according to changing circumstances
and needs, interface maintenance could be performed with less effort, etc. All good
stuff, but could all this flexibility also lead to confusion and reduced process overview? Operators were concerned. A study was initiated by the US Nuclear Regulatory
Commission ( NRC, 2002) to investigate the effects of interface management tasks on
operator performance. It concluded:
When HSIs [Human System Interfaces] are spatially dedicated, operators can use automatic information processing capabilities, such as scanning and pattern recognition, to
rapidly assess plant situations. The flexibility of computer-based HSIs and their general
lack of spatial dedication causes interface management tasks to be more dependent on
controlled information processing. The flexibility also makes it easier for operators to
mistake one display for another, and may cause them to improperly assess a situation
or operate the wrong piece of equipment.
( O’Hara et al., 2002, p.7)
The study also noted that operators were less likely to perform interface management tasks during stressful situations, relying instead on information that were
immediately available to them. That operators coming from an analogue control
room to a digitalized one often find it difficult to get a proper situation overview
is supported by the research performed at IFE Halden for the nuclear industry ( e.g.
Kaarstad & Strand, 2010; Kaarstad et al., 2008). This helps explain why “ information
hidden from view” is indeed a challenge for DPOs. During our interviews, we noted
several statements related to this. One said: “ He who sat there [at the DP desk] before
might think he is the world champion and has changed everything around. Very
many might then miss important information, especially signals that point towards
things that can go wrong.” Another stated that “ if the information is not already on
the screen it will not be used”.
This point toward a potentially effective design measure for digital control environments that is increasingly becoming industry standard in the nuclear and petroleum industries: The “ spatially dedicated” overview display.
HMI Measures for Improved Sensemaking
one the DPOs need to make a correct assessment of the situation and to best evaluate
the effect of any countermeasures that are being made. It could be that the current
user has actively organized the screens to best fit the planned situation ( and thus not
necessarily for the developing o ff-normal situation) or that the previous user has
arranged the screens to fit his or hers personal preferences which may not entirely
serve the current user and situation. But since the screens can be re-configured at any
time by the users, why is this a problem? Why cannot the DPOs simply reorganize
their screens to best fit changing circumstances?
When the nuclear industry began digitalizing powerplant control rooms, similar
issues were raised. In the old, analogue control rooms, every process function and
every component had its own dedicated, analogue control mechanism, located at
a fixed position in the room ( so-called “ spatially dedicated” interfaces). The new
screen-based control systems on the other hand were highly flexible ( user configurable), and the users could bring up any component or any piece of information on
any screen. By system developers this was considered an advantage: more compact
control environments could be made, more powerful information graphics could be
designed, control functions could be organized according to changing circumstances
and needs, interface maintenance could be performed with less effort, etc. All good
stuff, but could all this flexibility also lead to confusion and reduced process overview? Operators were concerned. A study was initiated by the US Nuclear Regulatory
Commission ( NRC, 2002) to investigate the effects of interface management tasks on
operator performance. It concluded:
When HSIs [Human System Interfaces] are spatially dedicated, operators can use automatic information processing capabilities, such as scanning and pattern recognition, to
rapidly assess plant situations. The flexibility of computer-based HSIs and their general
lack of spatial dedication causes interface management tasks to be more dependent on
controlled information processing. The flexibility also makes it easier for operators to
mistake one display for another, and may cause them to improperly assess a situation
or operate the wrong piece of equipment.
( O’Hara et al., 2002, p.7)
The study also noted that operators were less likely to perform interface management tasks during stressful situations, relying instead on information that were
immediately available to them. That operators coming from an analogue control
room to a digitalized one often find it difficult to get a proper situation overview
is supported by the research performed at IFE Halden for the nuclear industry ( e.g.
Kaarstad & Strand, 2010; Kaarstad et al., 2008). This helps explain why “ information
hidden from view” is indeed a challenge for DPOs. During our interviews, we noted
several statements related to this. One said: “ He who sat there [at the DP desk] before
might think he is the world champion and has changed everything around. Very
many might then miss important information, especially signals that point towards
things that can go wrong.” Another stated that “ if the information is not already on
the screen it will not be used”.
This point toward a potentially effective design measure for digital control environments that is increasingly becoming industry standard in the nuclear and petroleum industries: The “ spatially dedicated” overview display.