We use a mix of both. As security applications engineer, one of my responsibilities is to produce drawings for security projects in our Washington, Oregon, and Alaska branches. For some mid-size and almost all large projects, I send out the drawings to a local company that specializes in security design and CAD work. I do the design, designating what gets connected where and how, and also provide the CAD blocks for the access control components, so the drawings and installations are consistent whether the drawings were done internally or externally. This works out well because I usually don't have the time required to focus on drawings for large projects, and the large drawing packages look better than what I could produce (my expertise is really in security, not CAD). The outside firm also has staff that work over the weekend, which results in quick turnarounds. When the completed drawings come in, I review them for accuracy before releasing them to the project manager.