The semiconductor industry is rapidly outsourcing manufacturing and with that losing control of a key element of the supply chain. The success of memory companies is still intimately associated with fab ownership but most other semiconductor companies have outsourced a proportion of manufacturing. It is possible to get insight into the extent of the outsourcing by investigating how much revenue is created by every dollar of Property, Plant and Equipment (PPE). Fully fab'ed companies typically generate less than 2$ of yearly revenue for every 1$ of PPE they own, for fabless companies, it is typically over 8$. The chart does not reveal what model is the best - this is fully dependent on the company its strategy and the market cycle.
A timeline view of the Revenue/PPE data can reveal the strategic mode of a company. When Microchip acquired Atmel, they also inherited manufacturing capacity. In all likelihood, this is not part of the long term strategy of Microchip that is in the process of moving their revenue to foundry based manufacturing.