How old is your string? If it's over two years old, have someone knowledgeable take a look at it.

Do you shoot a lot or just during the season? If you shoot a hundred arrows a year, it won't wear as much as if you shoot a hundred arrows a day.

Where do you store your bow? What matters here is the temperature where it is stored. If you keep it in the back of your car all summer long, replace it immediately and stop doing that! Heat killsstrings and is bad for bow limbs too.If it's stored in the closet in your bedroom, it likely hasn't been damaged by heat.

As the others have posted, a little serving separation is almost normal. However, it helps to know why it is separating in order to make a good decision.