How to Identify Winning Stock/Share for Long Term Investment.

My book is on stocks and shares it talk about various valuation parameter, means financial checklist, which you need to apply before purchasing any shares/stocks. if your stock is not able to perform as per my valuation parameter then you should sell it and purchase some other stock which is OK on my valuation parameter, no point of holding that stock indefinitely,  generally you should check every stock once a year or twice a year, not more because certain times stocks are down or fail on my valuation parameter which was ok on my valuation parameter earlier as they have invested in R&D or invested for new product launch or for have some expansion plans, this strategy you can't master in few months for that you need to develop reading habit, generally you should be updated with financial news/article.