The phrase "unsafe system" is correct and usable in written English.
It is typically used to describe a system that has vulnerabilities that could lead to harm or danger. For example, "The company implemented a more secure system after their previous unsafe system was hacked."
At the point where human error exists to create an unsafe system, a problem occurs.
"It's a really chaotic and unsafe system".
If the response delay is relatively large due to practical limitations (for instance due to a long FMT), then the ramping rate must decrease, to avoid large power oscillations and unsafe system operation.
Unsafe system behaviour stems from the behavioural safety constraints not being met (Leveson 2012).
There is a notable lack of such assessments, meaning that there is a risk of accepting an unsafe system.
At the outset it is important to note that in using the terms safe system and unsafe system we do not mean to infer the existence of inherently or irreversibly safe or unsafe work-based sociotechnical systems.
However, it was well into the forties before all electrically unsafe systems were replaced by safe units.
In this period, but also thereafter until all unsafe systems were replaced by shockproof units, many people died or were seriously injured by electrical accidents.
This research aims to provide a solution for small scale miners using ill-designed and unsafe systems for hoisting and hauling purposes in their mines.
Our intent has been to examine sociotechnical system properties that can help distinguish safe from unsafe systems.
The fifth paper, written by Kleiner et al. (2015), integrates issues and themes from the prior papers in a discussion of sociotechnical attributes of safe and unsafe systems.
