What Are Design Constraints?
Product design constraints are limitations, rules, or boundaries on the design of a product. Examples of constraints could be a budget, a brand guideline, or a legal restriction. The word “constraint” definitely has a negative connotation. Some product developers view design constraints in a bad light because they feel like they’re being boxed in by a brick wall. While others embrace design constraints as directional guidelines that open the doors to creativity and strategic problem-solving.
9 Types of Design Constraints
Experienced product developers welcome design constraints as they work to create the best solutions to problems. As the old proverb that roots back to Plato says, “Necessity is the mother of invention.” Problems or constraints lead to new ways to think outside the box. The big overarching constraints for any new product are user desirability, production feasibility, and commercial viability. But developers face several others. Below are the top nine categories of design constraints that designers and engineers face every day.
Commercial constraints are common and involve factors like tight budgets, strict timelines, and limited manpower.
Functional Requirement Constraints
Functional requirement constraints focus on what the product needs to do, and what the specific features and functions need to be.
Nonfunctional constraints relate to intangible elements or qualities of a product. Examples of nonfunctional requirements could be ambience, security, and sustainability.
Compliance constraints include laws, regulations, or standards that must be met for the product to be viable.
Style constraints are visual guidelines relating to the product’s brand identity and aesthetics such as form, colors, and materials.
Sensory constraints are guidelines around how a product impacts the sense of taste, touch, sound, and/or smell.
Usability constraints are design principles and frameworks that feel intuitive and do not surprise users such as the principle of least astonishment.
Principle constraints are specific design processes or principles of an individual, team, or an organization. For example, DISHER uses a front-end design process for new product development.
Integration constraints include how a product needs to work with other processes, products, controls, or technology. Integration has become a growing design consideration with the advancements in cloud computing, mobile devices, IoT, and big data.
Design Constraints Open the Door to Creative Thinking
The DISHER team has found that design restrictions often force exploration and innovation. Design constraints help shape unique solutions that are just right for our clients and their customers. Constraints are healthy and help bring definition. In fact, one study shows that individuals, teams, and organizations can actually innovate better by having constraints. DISHER has found this to be true along with other experts like Tim Brown of IDEO who states,
“Design thinkers pose questions and explore constraints in creative ways that proceed in entirely new directions.”
As a product design and development engineering firm, DISHER works with a variety of constraints with every project we tackle. For our team, design constraints stimulate creative problem solving and lead to superior solutions. Let’s look at a few examples.
Real-World Design Constraint Examples
PCB Design Constraints
DISHER electronics engineers designed a circuit board to trigger an IR LED to flash at a precise time for use in a scientific instrument. We had the PCBs built and tested and they were working great. Then our client added a new design requirement, but they did NOT increase the budget or the timeline. Instead of drawing a hard line and going back for more money and time, our team buckled down to see if we could change the existing design to meet the new requirement with the PCBs we already had.
We could get 50% of the way there by swapping out a component and cutting some copper. Then one of our engineers came up with an innovative idea to use two boards back-to-back, keeping one board exactly how it was originally designed, and adding a second board in series with it that was modified slightly. When combined, the two boards met the new requirement.
Not only did our design meet the new requirement within the original budget and timeline, but we also gave our client an extra feature. They could add this extra board in front of the original board, or they could choose not to. This granted our client new functionality they didn’t asked for but greatly appreciated. The design constraints led to greater innovation.
Mounting Bracket Design Constraints
DISHER mechanical engineers were working with a client from the furniture industry. Our client was launching new privacy screens that were made of a very soft corrugated foam and wrapped in fabric. Our team was challenged with designing mounting brackets to hold the screen to a worksurface with the following functional and commercial design constraints:
- Ability to hold the screen in a vertical position
- Strength to withstand a swinging sandbag impact
- Weak enough to bend or break out of the way if someone fell on the screen
- Less than $1 per bracket
- Be invisible to the user so only the screen was seen – no visible brackets above worksurface
- Be invisible so when light shone on the screen you could not see a silhouette of the internal brackets
The team brainstormed a variety of possible solutions and came up with a four-piece plastic bracket made of two symmetrical pieces. The pieces that attached to the worksurface were glass-filled nylon for strength and rigidity. The vertical stanchions that kept the screen plumb were clear polycarbonate. We inserted two brackets into a hollow part of the screen and snapped them together. Initially the constraints appeared to be impossible, but in the end they yielded a pretty cool solution that our client was extremely happy with.
Medical Mattress Tester Design Constraints
DISHER engineers were tasked to build a reliable end-of-line tester for a medical mattress air pump. The testing device would be located at the end of the manufacturing line and be connected to every built unit to prove proper assembly.
A few of the commercial, functional, nonfunctional, integration, and usability design constraints for this project were as follows:
- Timing was critical. The EOL tester needed to be developed quickly to keep up with the manufacturing timeline.
- The tester had to replicate finger presses on buttons in a specific order, determine if LEDs were illuminated at the correct times, and monitor several transducers for flowrate and pressure.
- The tester had to be easy-to-use, require minimal maintenance, and work around a language barrier.
- There were no previous designs for this type of tester to learn from. The design would need to be created from scratch.
Using the rapid prototype design methodology, our team was able to identify the best microcontroller, solenoids, and sensors to meet the requirements through trial and error. We inversed the pump injection mold in CAD, and created a 3D printed “hat” that fit perfectly on top of the finished pumps. Finally, we modified the CAD to include the chosen hardware so this “hat” could now press all the buttons using the solenoids and sense the output air pressure and LED status. The device was made for easy use with labeling, an LCD screen with clear Pass/Fail status, and one-button operation. The list of constraints fostered creative problem solving.
Furniture Style Design Constraints
A unique project that DISHER’s industrial design and marketing team worked on together was creating style design constraints for a furniture manufacturer. Our client came to us with the need for style guidelines with visual brand language for their furniture products. They needed the guidelines to help their product design and development stakeholders create innovative product lines while providing a memorable and consistent brand experience for their customers. Instead of working within constraints, we were creating style constraints to strengthen their brand.
Our team put together several mood boards to represent their primary design pillars. We also created a design glossary with written and visual definitions including the periodic table of form, the Golden Ratio, and the Rule of Thirds. Then we assembled visual and written design guidelines for each of their product systems while applying the design principles and rules. The goals for the style guide included the following:
- To unify their teams in a clear direction
- To build a cohesive product line style strategy
- To increase brand recognition and a competitive advantage
- To realize efficiencies in new product development
- To make sound product line decisions within a solid framework
This project clearly shows the value of style design constraints in developing creative products that conform to a desired brand identity and experience.
3 Benefits of Constraints in Engineering Design
Entrepreneur Aza Raskin states, “Design is the beauty of turning constraints into advantages.” We agree. Design constraints open the doors to the following benefits:
1. Spark Creativity and Innovation
Constraints help product development teams cultivate new solutions. Innovative designs can increase the product’s value for customers and differentiate companies in the marketplace for increased sustainability.
2. Focus on Human-Centered Design
With design constraints already set, product developers can spend more time understanding and empathizing with users. Products that have strong user desirability with positive user interactions increase their success and sustainability. Human-centered design always leads to higher-level solutions.
3. Save Time & Money
Design constraints help product development teams focus. Engineers have a definitive starting point. Time is not wasted going in an irrelevant direction. The more time you save in the process, the more money you save. It’s a win-win.
Experience the DISHER Difference
What sets DISHER apart in product innovation? Our award-winning team. We have exceptional people, advanced tools, and proven processes that encompass the full spectrum of advanced product design. Our deep team of over 100 engineers and degreed experts come alongside clients in every phase of product development—from ideation and prototyping to detailed engineering and design for manufacturability. We tackle innovative problem solving from all angles—user desirability, commercial viability, and production feasibility. Our cross-functional team of engineers embrace design constraints as they inspire our team to problem solve at the next level. Having worked with over 1,000 clients from a diverse set of industries has added to our ability to leave this world better than we found it.
Create Great Designs with DISHER
Let us know how we can help turn your design constraints into innovative solutions! We can’t wait to help you differentiate your products in today’s competitive marketplace for long-term success and marketplace sustainability. We want to make a positive difference with you.