Mainframes are expensive – no-one disagrees with that. But what they can do is run industrial strength workloads for less than it would cost on other platforms with much less likelihood of any kind of system malfunction. Having said that, it makes sense to understand mainframe performance and ways that those costs could be reduced.
Let’s start by looking at performance and performance management. Here are some of the metrics used by performance-monitoring tools (also see Does Your Mainframe Need an Oil Change):