If the answer is no. If the answer is yes. If you lose the capacity and skill what is the probability that you will need it in the future and what is cost of replacing the lost capacity and skill in the future. Dependent on the answers to the above you keep the work in-house or you may outsource. However, additional questions must be answered first.
Overhead burden is a function of workload.
The more you outsource the more costly in house work become. Chicken and Egg Problem. The more you keep work in house the lower the overhead burden. The above are just a few of the issues that must be dealt with realative to outsourcing. The value of in-house capability is also proportional to the technical sophistication of the product, the price of the item, and type of product.