The two major factors considered for higher ranking in SERPs are the Page Authority (PA) and Domain Authority (DA). These two factors are what differentiate a high-ranking website from a low 
- Receiving more links from several websites
- Receiving fewer links from high rank websites
Besides traffic generation by PPC advertising, the PA and DA also have a crucial role in ranking of a website. The lines below give a detail of competitive analysis with the help of an online analysis tool based on PA and DA.
Start:
The first step is of the selection of the keywords for which you want to analyze the competitors. To have a better view of the SERP competitors, you must choose at least 20 valuable keywords.
Selection of Tool:
There are many internet marketing tools available online that will help you in analysis of SERPs competitors. However, before the selection of any of the tools, remember that it must provide following information about the competitor:
- Ranking in the SERPs
- The domain authority of the competitor
- The page authority of the competitor
- The number of linking domains
Once the tool displays a list of competitors, then you need to select the one competitor you want to compete with.
PA Analysis:
The biggest factor affecting the ranking of a website is the Page Authority. The tool used to get information about the competitor, can further be used to get an insight to the authority of pages linking to the competitors.
By using the information in competitor analysis, the tool will further give you a graph of competitor’s PA, which you can use to correlate with your own website and see what your website is missing in terms of receiving links from high PA websites.
DA Analysis:
The strength of a backlinking website is also important pertaining to the ranking of a website. The tool that gives you the PA of the websites linking to your competitor, will also give you information regarding the Domain Authority of the websites that give backlinks to your competitors.
SERP Analysis Report:
The analysis tool will give you a final SERP analysis report at the end, in this report you can;
- Get the data about the competition for each of your keyword
- Export it into Excel.
- Paste the provided data into spreadsheet.
- The spreadsheet will show different graphs, by comparing them you can find where your website lags behind from the competitors.
Conclusion:
In short, the online tool can greatly help you in doing competitive analysis, especially if you take PA and DA as the basis of it.