Add in finding the force components along the members, and you have a handful of math. If the number of joint where increased to a more reasonable 15 joints, there would be more work than most are inclined to compute by hand. This is where the computer comes in. Besides reducing arithmetic errors, it can solve for an extremely large number of equations within a fraction of a second. A computer application could certainly be useful for checking hand work, or solving large trusses where it would be too time consuming to do the computations by hand.
Trusses can support large loads without adding too much to the overall mass of an object.
By making a bridge out of a truss, a thinner road base can be used. Overall, a truss is just more efficient. It can support large loads by redistributing the force, it costs less, puts less stress on the supports, and has greater mechanical advantages over a slab of material. The program is a simple truss analysis tool. Other functions include saving of the truss and summaries, and printing.