There are innumerable situations which will lead to changes in this design, but all else being equal, this design is a very economical, code-compliant starting point for the stair-design process.

What are the advantages of this design?

This design is advantageous because of its relatively few number of components which can be pre-fabricated and brought on-site, minimizing the amount of field-welding which is required.

Additionally, It presents a simple load-path. Assuming that the bottom stringers are connected with a slotted connection, lateral seismic loads are transmitted to the primary structure only by way of the upper stringers

What are the disadvantages of this design?