What is the Importance of Tolerance Design in Six Sigma?

No matter how much effort you put into the design and production of an element, you can never guarantee it will be perfect in every way. In fact, smart leaders around the world have caught onto that, and those who understand the concept well enough know that they should actually design around the idea of failure as best as possible. In the end, certain kinds of issues are unavoidable but making sure our products can withstand them is not that difficult at all when you know what you’re doing, and it’s the main angle of attack for many organizations nowadays.

Tolerance Design for Sustainable Results

Tolerance design is the idea of building products with a certain level of tolerance built-in, and actually ensuring that they have the capability to perform when within those tolerance limits. This may sometimes mean stretching the boundaries of a certain material’s properties, for example, or making a part slightly larger than it really needs to be.

The point is that you should never design products around the idea that they will be perfect in their lifetime, and you should ensure that they have some built-in tolerance for the main types of faults that they can endure. Doing that is the best way to end up with a faulty batch that has to be discarded completely, not to mention all the extra effort that will have to go into redesigning the element from the ground up afterwards.

Different Types of Tolerance

When designing with tolerance in mind, there are several different types of tolerance that you’ll need to consider, depending on the type of product you’re working with in the first place. A common example in mechanical engineering is the physical distance between objects. When there is a lot of friction at a certain point, or other types of harsh movements that can damage the surface of the material, it can often be a good idea to create a small imperfection that can take the majority of the force.

This is also valid for situations where an object is moving along a set path, in which case you may need to provide additional clearance for cases where the system is malfunctioning and the object might swing farther away than intended. Simple adjustments like these can save a lot of time and effort in the long run when your designs work much more predictably, even when they encounter problems.

The idea of tolerance can also be found in software engineering. Allocating extra buffers even though they should never be filled, giving a longer timeout to a procedure, etc. these are all things that software developers typically do to make their programs more robust in the face of possible random failure. And in the real world, these small tolerance design features can actually save a lot in the long run when using a complex program. After all, having your memory filled with a little extra garbage data is much more preferable to the idea of having the whole program crash, losing all your data.

Knowing when and where to use tolerance design is a tricky ordeal, and it requires a lot of expertise with your specific field. That’s why some companies even give dedicated positions to specialists working in this area, as it can be very useful to have a good insight into the processes of the organization, and know where things need to be designed with more leeway and flexibility.

With time, you should also start to gain some intuition about what makes good tolerance design, and what features you need to be wary of when developing the systems of your own organization.

Conclusion

Tolerance design is a field that can take a lot of time and experience to master, but it can lead to significant improvements in your overall productivity and performance in the long run if you do it right. If you feel like you’re having trouble making sense of where tolerance design should be applied, just make sure you have someone experienced enough on your team to guide you through the process. But at the same time, do your best to catch up as quickly as possible too, as you’ll need the knowledge later.