Warning: This is an alpha release, for previewing of mechanics. It is not finished! (investigations aren't added for yellow and purple science, investigations are instant, investigations are instant, there's no unique graphics, and more)

Have you noticed that when you automate a technology pack, you get all of the technologies of that tier even if you're not ready for them. You get to do all these things with oil but you're focusing on trains, and the order of research did not really matter? This mod changes that by having you build enough of the product needed to make the technology useful before you can research it. So, for example, if you want to research oil processing, you first have to investigate some oil first.

When you start the game, you are given an investigation lab in your initial inventory. It's your only one, so don't lose it! Feed it the materials requested by each tech and you'll be able to then research the tech normally. Note though, that you have to manually feed the materials, since you have to also set up the tests for the investigation.