How Do Engineers Evaluate Different Design Ideas?

How Do Engineers Evaluate Different Design Ideas_

One of the very first steps in the engineering design process is idea evaluation. Engineering design services generate new ideas through brainstorming, either individually or with a group of people, to make simple documentation of the proposed designs and perspectives from professionals of different backgrounds. Every idea needs to be evaluated first to compare its technical feasibility and potential market success.

There can be plenty of ideas gathered during the brainstorming section, but engineers cannot develop all of them, as it will take too much time, energy, and money. Instead, they perform multiple analyses to determine one idea to be taken through further stages of development. Types of analysis depend on the nature of the problem and proposed solutions. 

Functional Analysis

A fundamental part of design evaluation is functional analysis, determining whether the proposed solution will work as it should. It doesn’t matter that the given idea meets all other criteria and constraints – if it cannot function well, it’s a failure from the get-go.


This is why functional analysis comes before all other types of evaluation. Once design engineering services figure out the idea is not worth developing, they should leave it behind so the work on another more plausible solution can begin as soon as possible.

An excellent historical example of proper functional analysis happened in the late 19th century with the ballpoint pen’s invention, credited to an American inventor named John J. Loud. Early designs had the right components, including a small rotating steel ball held by a socket at the tip. The pen worked on rough surfaces as Loud intended, but it was too coarse for writing on paper.

At that time, there was no commercial viability either, so he abandoned the project altogether. As groundbreaking and brilliant as Loud’s idea was, he couldn’t find a feasible method to improve the imperfections. His design idea for a ballpoint pen failed functional analysis.

It would take more than four decades until someone else continued what Loud had left behind. It was a newspaper editor named László Bíró who successfully improved the ballpoint pen using the design and mechanism we know and use today. Thanks to 20th-century precision manufacturing capabilities, we have a reliable ballpoint pen that writes smoothly on paper and does not leak.


The human factor of mechanical engineering services isn’t only about personal preferences and style, but more importantly, ergonomics. Many products are intended for use by humans, so engineers must study and understand how people interact with objects.

A product’s intended user is a significant factor in the design idea evaluation. People occupy a space around the design, and they may provide a source of control to determine how the product works. For example, a car has buttons and knobs to activate features like headlights, turn signals, air-conditioning systems, and a radio placed within reach of the driver’s position.

Modern cars have a tilt and telescoping steering column to accommodate drivers of different heights. Driver’s seats are also a big deal because they have to support comfortable sitting postures while still allowing for easy movement in and out of the vehicle.

Chances are your chair has been engineered with ergonomics in mind to keep you comfortable in a sitting position for many hours. An illustration below from Wood Magazine conveys how complex an ergonomic design idea evaluation can be.


A design solution is considered well-made if the shape, size, dimension, material, and control scheme or interface fit the people who use it. Geometric properties like natural movements, height, weight, circumference, reach, viewing angle, posture, and so on are known as anthropometric data. Different products require a different set of anthropomorphic measurements. It is nearly impossible to design something that fits everyone, so it should at least be comfortable and easy to use for most.

Safety and Liability

Concerning ergonomics, another critical consideration in design idea evaluation is safety. A product must be engineered so that it does not cause harm or injury to users. Liability refers to cases when engineers, manufacturers, and other parties involved in the design of a product can be held responsible for any injury resulting from the use of that specific product. Furthermore, the issues concerning safety and liability evaluations can extend to include environmental and property damage.

There are many different methods to make sure that a product is safe to use. SolidWorks engineering services can design safety directly into the product itself. For example, airbags in cars and binding release/brakes attached to ski boards. Safety evaluation is almost always tricky because engineers have to create various scenarios in which the product is subjected to injury-causing circumstances like a crash test. The point is to demonstrate how the safety devices will react or respond to the situation.

Another method is to devise protection for users, especially when inherent safety is too challenging to build, such as rotating or moving parts. Products like a table saw and lawnmower always present a risk of injury even when they work without issues.

To protect users from sharp rotating blades, the products come equipped with protective shields covering the blades in areas where they are otherwise too dangerous to be left uncovered. Warning labels do not protect users from injuries, but at least the products come with reminders that accidents may happen unless users take precautions.

Commercial Viability

Some ideas never make it to mass production because the manufacturing cost exceeds what people are willing to spend—for example, fully autonomous vehicles and jet suits. Although the freelance civil engineers themselves may not care if their design ideas have strong market values, their companies and employers do. Many engineering designs are commissioned by private for-profit entities whose end goal is to make profits by selling products. Therefore, the design idea has to be evaluated against commercial criteria—for example, cost of manufacturing and sales features.

Market research and surveys help determine what the target consumers want and whether there are competing products available. Engineers probably are not directly involved in telephone or personal interviews with random people, but they use the data collected from the survey for design evaluation.


If similar products exist, it is good to know how much they sell for and how well they perform – that way, engineers have reliable points of reference on how to outperform existing products, either by introducing improvements or removing unnecessary features to lower the price.

In reality, there is no way that manufacturers know with certainty any particular product will sell and profit. Consumers change their minds, and the market sometimes follows unpredictable trends. The best thing manufacturers can do is have multiple products designed and evaluated by qualified CATIA design services to improve their success chances.

Mechanical Analysis

To ensure good product performance, freelance reverse engineers need preliminary analysis of its mechanical features. Any kind of product, device, or machinery must be built to withstand repetitive shocks and dynamic loading for prolonged periods. In other words, only the structurally-sound design idea will continue to further stages of development. Analysis methods depend on the nature of the product; there will be different tests to check the structural integrity of shoes, smartphones, and guns, for example.

Some products generate heat when in use. Engineers must determine how much heat the product can withstand before it begins to malfunction, catch fire, or breakdown. Thermal analysis is necessary to figure out the heat dissipation process in a product. Electronic equipment can fail prematurely if the heat generated from electricity cannot dissipate quickly enough.

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In a complex system like a smartphone or computer, a single component’s failure due to excessive temperature can render the entire device useless. Intel had to postpone its early Pentium processor production because the microcircuit could not perform at its rated speed due to overheating issue. Once engineers sorted the problem out, the processor made its way to the market.

Mechanical devices will deform or deflect when subjected to applied loads. A change in structure is not always the result of intended use but exposure to extreme temperature elements. Some engineered-systems are indeed designed to deform, albeit to a small extent, to compensate for environmental conditions. A massive system like bridges and skyscrapers are not just challenging to test but close to impossible. Engineers often turn to mathematical models and computer simulations to determine maximum weight capacity.

Making the Decision

Once all the necessary analyses are completed, engineers can create a quantitative basis for determining which idea scores better than the alternative. For example:

  • Safety: 30 percent (30 points)
  • Function: 20 percent (20 points)
  • Ease of use: 20 percent (20 points)
  • Strength and durability: 10 percent (10 points)
  • Commercial viability: 10 percent (10 points)
  • Manufacturing cost: 10 percent (10 points)

An idea can be better in terms of strength and durability than the alternative, but it scores worse in the ease-of-use department. It can all happen in other areas of analysis, which necessitates quantitative judgment. A flawless perfect-in-every-way design would score 100, but anything close to 80 – 90 should be good enough.

Now that engineers have analyzed all the necessary design areas according to criteria and constraints, they decide the best design solution to work on. Bear in mind that at this stage, engineers merely choose the most plausible idea based on the aforementioned analysis, so they still have a lot of work ahead of them before product development reaches the final stages. Selected design ideas still need to be developed, refined, and subjected to real-world performance tests.

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