3 responses to “Can a design be too robust?”

  1. Fluxor

    Frau, excellent post. I can really relate to it. I wish we had the luxury of overdesigning. Rather, most of our products are quite underdesigned. Management asks us whether how much risk is there if we don’t do A or B in trying to verify our designs. Of course, we don’t really know if we don’t do a proper analysis, which takes time we don’t have. So the engineers give an equivocal answer which is then interpreted by management as having low risk. So the product goes out the door, runs into issues in the field, and gets returned with all the fingers being pointed at engineers.

  2. Em

    I work in an industry sector where “design” tends to be a little more casual, focused more on mechanical fit than anything else, and tends to be based more on rules of thumb, gut feel, and even aesthetic, rather than calculations. I’ve worked at a couple of different companies in different ends of the same industry, and tradition seems to define the results. As a note, factors of safety in this industry relate more to component failure and warranty costs than to human safety.

    Company A built their systems like tanks. You could probably cut 20% of the material cost (finer frames, smaller actuators, etc.) and still have a system that would more than meet the requirements. Before I left there was a drive to reduce costs, but going to a more involved engineering process to actually calculate the requirements to get to a “just good enough” system would probably have massively increased the engineering time, so that was discounted fairly early on. In a way, it’s the opposite problem to what’s described above – there it could be beneficial to reduce the safety factors rather than overdesigning through “efficiency”.

    At Company B, the design standards are definitely less robust (and as a result have lower material costs), but this can result in damage to the equipment under unusual loading conditions (say, getting hit by a forklift, or poor preparation for transport). Spending the extra time to consider the unusual loading conditions would probably result in spending less on warranty, but the drive isn’t there to spend the extra time in design.

  3. Amitabh Shrivastava

    I agree on it as far as Management’s approach to design work. Also, they don’t apply all required resources on time. But the designer must be smart enogh to come over all such situations.

    I feel, using over designed products is making us poor on part of availability of natural resources. Say for example, if an engineer designs a simple coupling for a pump and taken greater than required factor of safety or used what was not failed earlier (you say it time tested). It impacts on consumption of steel used for making such couplings. And if these couplings are going to be used for millions of pumps, your design will impact natural resources by few hundred tons……and so on….

    A very balanced and producable design of everything is required to save the world from consuming unnecessary consumption of natural resources.