A recent illustration of the latter comes from the automotive industry. SoundAlert Ltd was formed in the mid-1990's to exploit directional alarm technology developed by a Leeds University professor. Having protected the technology by patents, the company pursued a licensing business model but went into administration in 2008.
The administrators subsequently pursued a different business model, selling the patents to Kent-based Brigade (BBS-TEK) Ltd. Brigade then pursued a manufacturing business model, in the course of which they asserted the UK patent against a competing vehicle alarm sold by Leicestershire-based Amber Valley Ltd.
This is but one of many ways of using intellectual property in engineering business. You should of course seek professional advice on your own particular circumstances.
