A hard Real-Time Operating System is distinguished by its strict adherence to the deadline or limits of the task stipulated. In case this deadline is missed, the results are catastrophic. For example, an airbag has to deploy within the perfect time frame. Failure to deploy may cause death or extreme destruction. It means that the deadline was missed.

1. Basic Classifications of Real-Time Operating Systems
Real-time operating systems, or RTOS, are designed to automate and accelerate
the process of decision-making in order to avoid an unwanted outcome.
An RTOS may support very simple tasks or extremely complex procedures.
Regardless, you need to know what kind of real-time operating system best
suits your situation to achieve your desired results.
3 types of real-time operating systems
• Operating systems are extremely customized. It is therefore almost
impossible to find two similar systems in different environments.
However, there are three major classifications determined by the mode of
operation.
• Hard RTOS. A hard Real-Time Operating System is distinguished by its
strict adherence to the deadline or limits of the task stipulated. In case
this deadline is missed, the results are catastrophic. For example, an
airbag has to deploy within the perfect time frame. Failure to deploy may
cause death or extreme destruction. It means that the deadline was
missed.
• Firm RTOS. With a firm RTOS, the need to stick to the deadline does not
have a catastrophic effect but the results are undesirable. An example is
a production plant where the quality of a product diminishes because the
deadline was not met. This will affect the reputation of the brand, profits,
etc.
• Soft RTOS. The effects of missing a deadline with a soft RTOS are not as
catastrophic as in the two previous cases. The processes can be reversed

2. or corrections made without much effect on the product or process. An
example is the creation of a database that is used for storage purposes.
3 core features of real-time operating systems
No matter which type of RTOS you choose, the basic design should consider
optimal deployment time and predictability. To this end, a real-time operating
system requires a variety of key features, including:
• A short context switching latency: it should take the least time possible
to save data for the current context in order to switch to the current one.
• Short interrupt latency: this is the time taken to interrupt a task, switch it
off, and activate the next one.
• Consistent and reliable timing: there should be no delays in switching
between tasks. There will be complications if one task ends early or
another is delayed waiting for something else to be completed.
• Real-time operating systems are usually highly personalized. Even so, it’s
important to understand the basic types of RTOS and core functionality to
ensure you select the best system for your business.