What If The Rules Are Too Hard To Follow?

What If The Rules Are Too Hard To Follow?

CX 94 Staging What If

One of the cardinal rules in developing safety systems is to engage with the users of the system when you’re developing the rules of engagement and to try to develop a set of rules that they are going to actively and diligently follow - something more substantial than just giving it lip service.

This rule applies equally when designing complex machinery control systems as it does if you’re dealing with something like, say, getting pedestrians to cross a road at traffic lights.

If a system is easy to use and, dare we say it, “user friendly”, then it stands a much better chance of having people use it the way that the designers intended.

In our pedestrian example, for instance, if the goal is to stop people crossing a busy inner city street except for where there are traffic lights, then you need to make sure that the lights aren’t so far apart that people won’t walk the distance to get to them, that they turn green often enough to make it not too annoying to wait, and that they stay green long enough to cross.

So how does this apply to the world of big machines in theatres?

We were recently at a very large and busy venue that is equipped with a forestage lift that travelled from stage to auditorium to orchestra pit and down on into the bowels of the earth. Said venue is also equipped with a top of the line power flying control system with all the bells and whistles and a very sophisticated door and handrail interlocking system.

A set of rules had been written for the system with the intention of preventing a fall hazard from being created by the lift being driven down from the stage and beyond if barriers weren’t in place across the front of the stage and in the auditorium.

This set of rules prevented the lift being moved at all if these barriers and handrails were missing, but the operators had a regular and quite reasonable requirement to move the lift only from the stage level to the auditorium floor and back again, which doesn’t create a significant fall hazard.

Now, any system can have component failures or sporadic “issues” from time to time, particularly when it comes to things such as electric door locks and magnetic sensors on moving door leaves, so there was, as you’d suspect, a “back door” in the system that allowed the safety sensors around this lift (door interlocks, handrails, stage barriers etc) to be temporarily bypassed, by an authorised supervisor, with a password. This allows a show to go on, even if a $25 magnet has failed in a lock.

Trouble with this system was that the lift is so often moved between stage and auditorium, and the barriers and handrails were so heavy and cumbersome, requiring 2 or 3 people 10 minutes or more to deploy, that “everyone” knew the supervisor login and safety bypass password, and the system was almost always being operated with all of the safety systems compromised.

All it took to rectify was to change the rules of engagement – now the lift can move freely between stage and auditorium, and if it is already below the auditorium it can be moved UP without needing any barriers in place. The operator now only needs to drag out the barriers when they are actually creating a dangerous fall hazard.

Because it is now easy to use and the users can see the logic and reason in the rules, then the system never gets bypassed.

Well that and the fact that all the passwords were changed so only supervisors have supervisor’s passwords...

Jands Staging
provide articles to the "Staging What If" section in CX Magazine. If you have any questions regarding this article then please comment below or email info@jands.com.au.

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