What do you think how many funds do we require in a portfolio say for 15 years?
And after 2 or 3 year if we feel any of fund is not doing good then we should quit that fund and start new ?
Old fund (which is not doing good) should be continue without investing further or should be reedemed?
Equity investing is not like investing in Bank FD and open eyes at maturity. Once in a year review is MUST. However, if funds underperforming continues for 2-3 years, then you must quit and go for new fund.
Quitting means coming out completely from old fund and investing in new. But do remember that how you judge the existing fund underperformance. Never run behind star ratings, never compare peers but check whether the fund is giving you the expected returns or not. If it is giving, then you MUST continue.