Closed systems

Suppose that there are 100 security flaws in a particular software project and we can list these flaws in such a way that security flaw i requires i hours of testing to find. That is, it takes one hour to find flaw number one, two more hours to find flaw number two, three more hours to find flaw number three, and so on.

What is the MTBF for this system?

This problem compares closed systems and open systems.

a. Define “open system” and give an example of an open system.

b. Define “closed system” and give an example of a closed system.

c. What are the advantages of open systems, as compared to closed systems?

d. What are the advantages of closed systems, as compared to open systems?

Solution: