Answer:
Yes, the spin off was successful.
With the major segments of fast food being sandwich chains, pizza chains, family restaurants, dinner houses, chicken chains, and more each Yum restaurant needed to be placed into their own niche. They also started using multi-branding and putting the brands in the same building. This allowed one location to draw in a more diverse crowd of consumers while offering them more variety and covering the other brands weak points.
Reason for their success.
PepsiCo, when spinning off these fast food chains, openly stated “restaurants weren't our schtick.” I.e the company presented themselves themselves to media that restaurants isn't focus. Before the spin off KFC, Pizza Hut, and Taco Bell often acted as their own entities and competed with each other resulting in lowered sales for all of the restaurants. With the spin off of Tricon the restaurants were unified with the sharing of many resources and using their collective clout, as one of the top five brands, to get better deals on ingredients all the restaurants share. Their concentrated focus allows them to be greatly effective in entering new markets such as Asia