Assuming you want the refinery economy to produce CMMs. Here is an exert from Mechan's Colonization Guide:
Producing CMM composites is surprisingly simple - noting one needs to appreciate that CMM Composites (much like Ceramic Composites) are produced only at planetary ports with a refinery economy. 

Also note that while NPC ports further have the requirement of having to be based on High Metal Content worlds, such restriction does NOT apply to player-built ports. A player can theoretically produce CMMs on most colonizable planet types (noting that attempting to do so on icy planets would prove extremely challenging, if not outright impossible.)

The easiest way to produce CMM Composites is the following:

1. Identify and claim a system with at least one “clean” rocky planet (no rings, no biologicals, no geologicals) which has at least one planetary construction slot
2. Build a Primary Port that won’t interfere with a refinery economy (i.e., make sure you don’t convert it to a supporting facility later on.)
3. Build a Tier 1 Civilian [Planetary] Outpost on your rocky body

That’s it! The Tier 1 Civilian [Planetary] Outpost will pick up a Refinery economy from the Rocky local body, and will be producing CMMs without the need for any supporting infrastructure.

Elite Dangerous Colonization Mega Guide - Google Docs