Question

Explain why the reliability of a system is not static but dynamic.?

Answer 1

First of all, let's understand the meaning of "reliability of a system":

• Reliability of a product is defined as the probability that the product will not fail throughout a prescribed operating period.
• It can also be defined as the probability that a system will produce correct outputs up to some given time.
• In computer science sense, a reliable system will always reply to a request in the given frame of time.
• If any system fails to perform the task in the given frame of time, it is said to be an unstable system.

Now, let's see why the reliability of a system is not static but dynamic:

• We can calculate the average load to a system but we don't know really, how much load we will be getting at an exact point of time.
• Let's say suddenly some news breaks and it is related to a particular organisation. So, a large bunch of people will start visiting that organisation's website and their system may become unstable.
• Entire network infrastructure is based on some hardware components, and it can fail anytime. For these situations, we design our infrastructure in such a way(having backup systems, using good quality hardware, replacing the old systems, properly designing the storage system, etc), when any component fails also, the entire system doesn't fail or the system remains stable.
• Many other natural and artificial reasons can also arise dynamically, so the reliability of a system also become dynamic.
• There are many things by which we can say the reliability of a system is dynamic. In broader terms we can say, the expectations from a system are dynamic, so its reliability will also be dynamic.

Please let me know in the comments in case of any confusion. Also, please upvote if you like.