Selective Outsourcing is a type of outsourcing which only focuses on certain functions which are considered as "priority ones" when outsourcing. This kind of method has its downside as well as its upside, depending on the company.

Let me share with you some advantages and disadvantages in selective outsourcing:
Advantages
-greater control on quality.
-less safety concerns for companies in terms of loss or damage
-additional choices for expert contractors
-replacement of contractors are much easier as compared to total outsourcing

Disadvantages
-possible confusion among workers
-higher security risk
-unskilled employees
-difference in quality and work output
-less values displayed like honesty and loyalty

This is a great list which you could use in order to decipher if selective outsourcing would be the best business strategy for you and your business.