It is said that SaaS/PaaS/IaaS is good for save cost. Actually it depends but we definitely can save human resource for maintenance it and this means we can focus on other business or work. Regarding to SaaS, for me, purchasing SaaS means purchasing IT system, and knowledge/know how based on world's best practice, it it's authentic one. Some company pays a lot for consultation, and after that, IT staff still need to discuss how to realize consultation paper as operational system, then they still need to pay effort for system development. Purchasing SaaS means all of them. And regarding to PaaS, I always propose system development using PaaS with process like agile development. PaaS limits possibility /flexibility of development to some extent, but it's a strong base of rapid development and helps quality by providing prepared function/framework. PaaS implementation has great potential of changing work style/culture.