Tests for an Argument to be Good

According to the Epstein text for an argument to be good it must pass three tests:
-The premises are plausible
-The premises are more plausible than the conclusion
-The argument is valid or strong

The tests don't depend on each other so if one fails, it doesn't necessarily mean that the others will fail also. If we find that it's possible for the premises to be true and the conclusion to be false then it is not a valid argument. If we know that the premises are true then the argument is good.

In order to be alive, your heart must be beating.
Richelle's heart is beating.
Richelle is alive.

Is there any way for the premises to be true, but conclusion false? Is there any way for Richelle's heart to be beating but she is not alive?

In order to be alive, your heart must be beating.
Richelle's heart is beating. Richelle is not alive. -This cannot be true.

Is the premise plausible?
The premise seems credible, valid, or true so yes, the premise is plausible.
Are the premises more plausible than the conclusion?
The first premise is more plausible than the conclusion because we can say Richelle is alive, but how do we get there? The conclusion seems credible, but the premises are more credible.
Is the argument valid or strong?
Is it possible for the premises to be true and the conclusion false? No, it's not, so then the argument is valid. Are the premises true? Yes, the premises are true, so the argument is strong.