The Railroad Requirements Document

 In my day job we have to create what is called a BRD, or business requirements documents, for large projects.  It is a vital tool for keeping a project on track.  For the model railroad I feel I need something similar - the RRD, railroad requirements document.  The purpose of the document is to establish the framework by which the project will be guided and judged for completeness and success.  As a project progresses new ideas will inevitably pop up but before action is taken on these new ideas they must be measured against the RRD to ensure they are driving towards the project goals.  Here are my requirements for my model railroad.

• Operational style - The layout will be a point to point switching layout with the option for continuous running.
• Layout style - The layout will be a walkaround island style.  The two sides of the layout will be separated by a backdrop divider.
• Model Period and Location - model is set in the Southern Pacific Phoenix sub-division between 1989 and 1995.
• Power and Control - The layout will use Digitrax DCC for control.  Power boost will be added as needed.  A separate power source will be provided for AC power.  Track feeders will be installed periodically to ensure power to the tracks.  
• Benchwork - The benchwork needs to be lightweight and modular.  The surface will be high density foamboard. 
• Track - The layout will use code 83 flex-track for the permanent track.  Code 100 sectional track can be used in the prototype and planning phases for proof of concept work.
• Rolling stock - All rolling stock will have metal wheels, kaydee couplers, and be properly weighted and adjusted.
• Motive Power - Southern Pacific 4 axle EMD power as primary.  Limited use of leased power or Rio Grande power per the modeled period.
• Industries that can be included - cement, lumber, plastic product manufacturing, paper product manufacturing, logistics centers, oil and fuel suppliers, grain and flower processing, food distribution and manufacturing, fertilizer manufacturer and distribution, chemical manufacturing
• Industry size - Industries should be able to handle 2 cars minimum of the standard car for that industry and a maximum of 4 standard cars for that industry.  The exception is when the standard car for an industry in 40' or less then the max is increased to 6 cars.
• Industry density - Each modular section pf the railroad can have no more than 2 rail served industries and it is preferred to have only one.  Inclusion of section without an industries is also preferred (negative space).

I think this is enough to get me started.  These are meant to be high level requirements and not the detailed design.  That comes later.  This should help keep me focused.