Introduction

Real-time systems are systems whereby the correctness of the computed values and their timeliness are at the forefront. There are two types of real-time systems, hard and soft real time.

What differentiates hard and soft real-time systems is their tolerance to missing deadlines and the consequences associated with those misses. Correctly computed values after a deadline has passed are often useless.

For hard real-time systems, missing deadlines is not an option. In fact, in many cases, missing a deadline often results in catastrophe, which may involve human lives. For soft real-time systems, however, missing deadlines is generally not as critical.

Real-time applications cover a wide range, but many real-time systems are embedded. An embedded system is a computer built into a system and not acknowledged by the user as being a computer. Embedded systems are also typically dedicated systems. In other words, systems that are designed to perform a dedicated function. The following list shows just a few examples of embedded systems:

Real-time systems are typically more complicated to design, debug, and deploy than non-real-time systems.