When making stew the stew should simmer for 3 to 4 hours until the meats and vegetables are fully cooked.
The time it takes to for stew to simmer to cook the meats and vegetables depends on the size of pot of stew that you're cooking.
But for an average size pot of stew 3 to 4 hours of simmering is enough to cook the meat and vegetables in the stew.
If you want to cook the meat faster then you could brown the meat first in a skillet and then add the browned meat to the simmering stew.
In that case the stew may only need to simmer for 1 to 2 hours depending on how you like your stew.
What I do to make stew is to get the stew boiling then turn the stew down to a simmer without the meat and just the vegetables and while the vegetables in the stew are simmering I brown the meat in the skillet.
Browning the meat makes the stew cook faster and also gives the meat in the stew a better flavor.
But you can add raw meat to the stew and just simmer it long enough to allow the meat to fully cook.