Aphorism List

Aphorism = terse statement of truth

Chapter 1. Why Study the Design Process?

• During the design process, product cost is committed early and spent late.
• The design process not only gives birth to a product but is also responsible for its life and death.
• Design problems have many satisfactory solutions and no clear best solution.
• The more you learn, the less freedom you have to use what you know.

Chapter 2: Describing Mechanical Design Problems and Process

• Decomposing a product by its form (i.e. components and assemblies) is great for manufacturing and assembly, but design focuses on function.
• Form enables function and function underlies form.
• Most design problems are redesign problems since they are based on prior, similar solutions. Conversely, most design problems are original as they contain something new that makes prior solutions inadequate.
• Design is the technical and social evolution of information punctuated by decision-making.

Chapter 3: Designers and Design Teams

• All design and decision-making is governed by human cognitive limitations.
• If you try to think about what you are doing while you are doing it, you stop doing it. If you don't reflect on what you just did, you are doomed to repeat it.
• A team is a group of people working toward a common understanding.

Chapter 4 The Design Process

• Design is a process not just building hardware. Tim Carver, Oregon State University student, 2000.
• Developing your only concept into a product without effort on the earlier phases of the design process is like building a house with no foundation.
• Quality can not be manufactured or inspected into a product. It must be designed in.
• Design is an iterative process. The necessary number of iterations is one more than the number you currently have done. This is true at any point in time. John R. Page, Rules of Engineering
• Follow the KISS rule: Keep It Simple Stupid!

Chapter 5: Project Definition and Planning

• Planning is like trying to measure the smile of the Cheshire cat, you are working with something that is not there.
• Planning is easier than doing, but much less fun.
• Plan to fail early and fail often.
• A task that only describes an activity is done when you complete the activity not when you have useful results.
• Everything takes twice as long.
• Never is often better than late. Sidney Love, Planning and Creating Successful Engineered Designs, 1980.

Chapter 6: Understanding the Problem and the Development of Engineering Specifications

• All design problems are poorly defined.
• You only think you know what the customer wants in your product.
• If you haven't set your targets at what your customers want, you only know you are done when you run out of time.
• Find the target before you empty your quiver.

Chapter 7: Concept Generation

• If you generate one idea, it is probably a poor one. If you get twenty ideas, you may have a good one. Or, he who spends too much time developing a single concept only realizes that concept.
• To steal ideas from one person is plagiarism; to be influenced by many is research.
• Function happens primarily at interfaces between components.
• Try to not reinvent the wheel.
• Complexity grows faster than you can understand it.
• It is hard to make a good product out of a poor concept.

Chapter 8: Concept Evaluation

• He who knows not and knows not that he knows not is a fool; shun him.
• He who knows not and knows that he knows not is a child; teach him.
• He who knows but knows not that he knows is asleep; wake him.
• He who knows and knows that he knows is wise; follow him. Old Arabic Proverb
• All decisions are based on incomplete, inconsistent, and conflicting information.
• The odds are greatly against you being immensely more knowledgeable than everyone else.
• Your product will fail, be ready!
• Complete and accurate evaluation takes knowledge. Knowledge development costs time and money, so compromise is necessary.
• If the horse is dead, get off.
• The problem with designing something completely foolproof is to underestimate the ingenuity of a complete fool. Douglas Adams

Chapter 9, The Product Design Phase

• A drawing is worth 1000 words, a good drawing worth even more.
• The designer who details before layout must have time to waste.
• The ideal is to represent a component only once - and from this representation produce drawings, components, assemblies, maintenance manuals and all other documentation.
• Managing product information is harder than creating it.

Chapter 10, Product Generation

• In mechanical design, form follows function.
• In industrial design, function follows form.
• Mechanical design progresses from function to form, yet ugly products seldom work right or sell well.
• Complexity occurs primarily at Interfaces
• Determine how constrained a component needs to be, and constrain it exactly that amount.
• Components grow primarily from interfaces.
• Forces flow like water.
• Failures occur mainly in the rapids. Freeze the design when you can see that changing it will take you until next summer.
• When in doubt,
• Make it stout,
• Out of things,
• You know about.
• Genius is 1% inspiration and 99% perspiration. Thomas Edison
• If it aint broke, don't fix it.
• Triangulate unless you have a good reason not to.
• Design perfection is achieved not when there is nothing more to add, but rather when there is nothing more to take away. Antone de Saint-Exupery

Chapter 11, Product Evaluation for Performance and the Effects of Variations.

• Every feature added brings with it new intended functionality. It is the new, unintended functionality that can hurt you.
• Costs generally increase exponentially with tighter tolerances.
• Nothing is deterministic, everything stochastic. In other words, there is variation in everything.
• An inaccurate model is inaccurate no matter how small the variation.
• Know how to control what you can, make your product insensitive to what can not, and be wise enough to know the difference between the two.
• Modeling always requires a clear head and more time than you thought.
• Hand fitting parts is fun when making a prototype, a disaster on the assembly line.
• She who does not design a robust product will be cursed with unhappy customers.
• You cant BS hardware.

Chapter 12. Product Evaluation for Cost, Manufacture, Assembly and other Measures.

• If you don't have experience with a manufacturing process you want to use, be sure someone is on the design team who has, before you commit to using it.
• Eighty percent of the cost is incurred by 20% of the components.
• The ideal product has only one component.
• Every fastener adds cost and reduces strength.
• A single part costs nothing to assemble. M. M. Andreassen
• You are responsible for the resources used in your products.

Chapter 13 Launching and Supporting the Product

• Documentation is like having to eat the poor crust of a good pie in order to clean your plate.
• Only a perfect product will never change.
• Patents give you bragging rights and a license to litigate.