Thanks to @kenjiskywalker, we had an opportunity we went to Kayac's office and gave our talks to them. I talked about software development process based on my recent thoughts. Here's the slides I used then:
In short, working process is to visualize invisibility (霊的存在). The more we visualize things, the more we can get accurate values. Since we're working in some organisation with many colleagues, there are lot of invisibility here and there. As I talked in the presentation, we have to achieve visibility against software feature and communication among development team.
Nevertheless, it's difficult without any help, so we can adopt agile development processes such as Scrum and many tools and practices. In my point of view, Scrum is to frame our activity to visualize invisibility. We hassle to solve problems without solving invisibility, then we tend to lose our way. What we do with at first is invisibility. Have more communication with appropriate understanding on invisibility.