Both these thinking processes should be combined to get the best outcomes.
Check this HBR article for a better understanding : http://blogs.hbr.org/martin/2010/01/why-most-ceos-are-bad-at-strat.html?cm_sp=blog_flyout-_-martin-_-why_most_ceos_are_bad_at_strat
Check this HBR article for a better understanding : http://blogs.hbr.org/martin/2010/01/why-most-ceos-are-bad-at-strat.html?cm_sp=blog_flyout-_-martin-_-why_most_ceos_are_bad_at_strat