There is criticism that SWOT is not very well structured, a hastily conducted exercise that produces unverified results.

It is clear that imprecise or vague reference in such an analysis to factors external and internal to an organization will always detrimentally affect communication and verification of proposed factors and thus lead to inferior outcomes of strategic analysis. It appears that this common flaw in SWOT analysis is caused mainly by misconceived SWOT deployment, insufficient levels of skills and diligence, and strategic information gaps.

I Agree.. But still its a great tool to understand you internal and external factors that effect your business. SWOT should be used for an initial analysis followed by tools like Competition Analysis and other techniques for understanding business .