Planning and Construction.

Greetings all!

Having watched nearly all the Wiring Harness Construction videos available on HP Academy, I am now pretty confident that I could construct a mock harness or a replica of an existing OEM harness. However, I am still deeply confused on how to plan and execute the construction of a custom harness. I want to build a custom swap harness for a VK56DE into a Z33 chassis. I have no clear understanding of how to go about plotting its design. Is it really as simple as creating a spread sheet of all the intended connector ends? What if I intend to add a staged Nitrous Oxide kit, OEM BCM harness integration, stand alone engine management system, kill-switch toggles, ect. The harness layout and construction seems pretty straight forward, but how to go about designing it is still a mystery to me. Are there any in-depth books or articles someone can recommend or explain it in a detailed or step-by-step manner to further my understanding?

Thanks everyone,

Nissan Jon.