Examination of Concrete Structures

What factors need to be taken into account before any decision is made about remedial action that may be needed when cracks are present?
You need to be more specific. Are you repairing the cracks, or are they present in an element that is being repaired for other reasons?

What kind of structure/element is involved?

A structural beam will require one approach while a plain slab-on-grade will require another.

By the way, where in the world are you, and how did you get to my web site?