Building a virtual appliance is not as easy as it may sound in your engineering department. Although plenty of smart engineers probably can build a one-off appliance, building it the same way again is a different story. If you think you might gain on short-term results by building a virtual appliance in-house, consider the longer-term price in terms of deploying, managing and maintaining the appliance. So, before you authorize your engineering department to build a virtual appliance, ask some important questions.