What is a range plan?

A range plan will give you an OVERVIEW OF YOUR RANGE, allowing you to get an idea of how the range will fit together, how the COLOUR OPTIONS will work together and enable you to get an idea of how you can MERCHANDISE your range to be the most appealing to the customer. This is the FIRST VISUAL LOOK at your range without having actual samples. 

This is an important part of the design process and it is worth having an idea of how you see you range plan in the early days of designing. Even if your initial range plan isa quick sketch it will give you an idea of how many bottoms you need compared to tops. Always have in mind the complete range when designing. If you are using a certain detail on one garment it may be worth using it on a few garments so it gives you a more cohesive theme to your range.
If you working on a range of tops, think about what you would put them with? Do you have the right bottoms so that a potential customer would buy both? Can you display them together, photoshoot etc? Your final range plan should also show colour options, a range plan is great for seeing the overall range with the different options of colour. You don’t want to go too mad on colour options initially. If you are a small business then you should be thinking of 1-2 options initially. 
Another point to think about when designing and putting your range plan together is to look at each design individually, is it too similar to another style? Would this split sales? Would it be worth just keeping the one style? Also think of fabrics, can you use the fabric on more than one style?Using fabrics across more than one style will help you when it comes to fabric sourcing and minimums order quantities.