I was tasked with creating a Flat-Pack chair for my engineering class. To be "Flat-Pack," a chair must adhere to the following criteria:

Made out of a single sheet of plywood
Easy to cut with a CNC or Laser Cutter machine
Be a (functional) chair
Support a persons weight
be comfortable
other chair things etc etc.

Supplies

4 foot x 4 foot plywood (3/4in thick)
CNC machine
fasteners (glue/screws)
Upholstery (fabric, padding, etc.)

Step 1: Preliminary Research

The first step in this project (as well as any other project) is to conduct some research before you even begin to think about what you're going to make. For this concept, there are already a lot of designs out there so inspiration was easy to come by.

When searching for flat-pack chairs, there are a few main designs I came across.

Lame, boring, uncomfortable stool
Lame, boring, comfortable chair with back
Cool-looking, incredibly uncomfortable / not functional chair
Cool-looking, comfortable chair that uses too much materials

Finding a balance between form and function, as with all design challenges, is a formidable task.

Step 2: Brainstorm Designs

The next step in the process is to start actually thinking about what you want the chair to be.

I wanted some kind of a stool. Since the average surface area of a stool is pretty low, I figured I could use more wood for elements that I wanted to incorporate into the design side of things, rather than the practical side. If I were to do a chair, I would need more surface area for the back and armrests, which would use more wood.

Step 3: Prototype

There are a couple different ways to prototype your chair, my class used a cardboard model, followed by a scaled down CNC machine cut model that was more accurate to the original design. In this stage, the most important thing to do is early testing, see if:

The chair supports a proportional amount of weight
not inherently necessary, just see if it supports any kind of stress
The chair has any racking / twisting
All of the tabs fit correctly
It looks how you want it to look

Step 4: Final Product

The last stage in the process is building the actual chair. Because of how much work you did beforehand, this step is absolutely the easiest. All you need to do is: