In the volatile internet and e-business markets with a dominating factor 'speed' we have to face rapidly changing market and user requirements. Subsequently we have to give up development guidance by traditional — ‘heavy weight’ — processes to be able to react quickly enough. The big challenge is to find the right balance between clear orientation towards quality and reliability goals on the one hand and improving the ability to deliver to the market with higher frequency. Process improvement based on the Capability Maturity Model has demonstrated its benefit all over the world, but in these times there are voices claiming that CMM is no longer suited to the fast-paced, flexible, and innovative development required in the internet age. Experience at Siemens shows a changing world of IT business with consequences concerning process improvement. When properly used, CMM is still an excellent guide for successful software development —also in these ‘agile times’.