If you're talking about manufacturing in regulated industries (e.g. Pharma) then also consider resources like Good Automated Manufacturing Practice (GAMP). There are a variety of standards that companies in this space must adhere to with respect to industrial control systems.
These aren't technical documents but they do provide relevant background to understand the landscape and might shed light as to why there is little "innovation".
Also, if you're at a place where they are implementing GMP, they probably have formal training and training records. It can be a good idea to look around the system and see what other online training outside your own discipline you have access to. A lot of the GMP documents that manufacturing people have to be retrained on annually will give you insight into why things are the way they are and what that particular company's way of handling processes looks like.
These aren't technical documents but they do provide relevant background to understand the landscape and might shed light as to why there is little "innovation".