how to do a swot analysis

VRIO framework. A resource can be seen as a strength if it exhibits VRIO (valuable, rare and cannot be imitated) framework characteristics. Otherwise, it doesn’t provide any strategic advantage for the company.
Some strengths or weaknesses can be recognized instantly without deeper studying of the organization. But usually the process is harder and managers have to look into the firm’s:

A SWOT analysis is a tool for documenting internal strengths (S) and weaknesses (W) in your business, as well as external opportunities (O) and threats (T). You can use this information in your business planning to help achieve your goals. To work out if something is an internal or external factor, ask yourself if it would exist even if your business didn’t. If it would, then it’s an external factor (e.g. new technology).
To get the most out of your SWOT analysis, you should have a question or objective in mind from the start. For example, you could use a SWOT analysis to help you decide if you should introduce a new product or service, or change your processes.

For one, conducting a comprehensive SWOT analysis provides a unique opportunity to gain greater insight into how your business operates. It’s all too easy to get lost in the weeds of the day-to-day workings of your company, and conducting a SWOT analysis allows you to take a broader, bird’s eye view of your business and the position it occupies in your industry.
Anticipating and mitigating the threats identified in your SWOT analysis may be the most difficult challenge you’ll face in this scenario, primarily because threats are typically external factors; there’s only so much you can do to mitigate the potential damage of factors beyond your control.

Here’s what the layout of a SWOT analysis looks like.
Threats are external factors that you have no control over. You may want to consider putting in place contingency plans for dealing them if they occur.

Weaknesses are aspects of your business that detract from the value you offer or place you at a competitive disadvantage. You need to enhance these areas in order to compete with your best competitor.
Continuing this process, use the opportunities you identified to develop strategies that will minimize the weaknesses (weakness-opportunity strategies) or avoid the threats (weakness-threats strategies).

References:

http://www.business.qld.gov.au/starting-business/planning/market-customer-research/swot-analysis/conducting
http://www.wordstream.com/blog/ws/2017/12/20/swot-analysis
http://www.liveplan.com/blog/what-is-a-swot-analysis-and-how-to-do-it-right-with-examples/
http://articles.bplans.com/how-to-perform-swot-analysis/
http://www.reverso.net/spell-checker/english-spelling-grammar/