Introduction to Engineering
Unit 3 Lesson 7
Reverse Engineering


The learner will:
  • Describe the concept of reverse engineering and why it is important to engineers.
  • Describe the process of reverse engineering and how it is similar to conventional engineering design.
  • Describe examples of industries that use reverse design and some specific examples.

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Item Instruction

Define the following key terms in your journal as you encounter them in the lesson:

  • reverse engineering
  • invention
  • innovation
  • continuous improvement
  • dimension inspection lasers
  • artificial intelligence

Reverse Engineering

Conventional engineering design typically starts with ideas, concepts, and specifications and then works toward a finished product or system.  Reverse engineering does just the opposite.  Reverse engineering is the process of taking apart an existing product or system to discover its specifications, concepts, ideas, and origination.  For example, reverse engineering (RE) can be used to discover how a product works or how it was made, especially if no design documentation exists or the documentation is unavailable.

Reverse engineering is also important to help develop new products and systems.  It can be used to help create something entirely new or an invention.  Generally, it is used to develop innovations, or the improvement or modification of an existing product or system.  Innovation is the process engineers use to keep their companies competitive and to develop newer products and systems.  Just think if humans had not innovated some of the devices introduced over the last century, such as the TV, telephone, or computer!  Our modern versions of these devices are more powerful, have more features, use less energy, and in most cases take up less space (unless you have a giant widescreen TV).

(Photo courtesy of Cornellanense, published at WikiMedia Commons and used under the following license.)

Innovations in product design often come from reverse engineering.  Consider how knowledge of old computer equipment might advance development of new generations of computers.  (Photo courtesy of NREL.)

Engineers and businesses have a variety of reasons to reverse-engineer products and systems.  They may be examining their competitor’s product, looking to improve their own products or increase the number of types of products they develop.  They may use reverse engineering to determine what is causing a failure to occur or to employ a company policy of continuous improvement, a process of striving always to improve their product, process, or system.  They may also use reverse engineering to help them change a product based on feedback from consumers on which design goals are more important.  For example, consumers may want more durability in a product (increased design goals) and are willing to pay more for the improvement (reduced design goal).

Reverse engineering techniques provide engineers with a wealth of information.  They document critical information on how a product was designed, how it operates, and even how it was manufactured.  They can also document what a product cannot do, point out wasted materials or processing time, or expose security flaws.  Documentation can be generated on specifications of materials, proportions, integration or parts or systems, defective parts or design, aesthetics, and other design characteristics.  Products or systems can then be redesigned and improved by retaining the good components or design and eliminating the bad components.

Reverse engineering can be used to determine and document what parts have failed and where to focus when redesigning.

Reverse engineering, although used often to study the competition, cannot be used to copy products or systems.  Patents are used to prevent this from happening (you will explore this in Lesson 9 of this unit).  Engineering ethical and legal codes prohibit engineers from simply copying a competitor’s design.  However, reverse engineering is sometimes used to modify a product or system by developing a new design that is slightly different and, hence, in compliance with patent laws.  Competitors from different countries may also use reverse engineering to develop products, as their own countries do not follow U.S. patent laws.  To help avoid the reverse engineering of their products, some manufacturers in response take extra precautions such as putting sensitive electronics into solid molds to avoid having them taken apart.

In 1947 the Soviets used an interned US B-29 bomber and reverse-engineered it to develop the Tupolev TU-4 bomber.  (Photo courtesy of the U.S. Government, published at WikiMedia Commons and used under the following license.)

RE Process

As with the conventional engineering design process, the reverse engineering process is not linear.  It can be explained as a series of steps, but the steps can be carried out in a different order or revisited whenever more information is required.  Various descriptions of the steps are offered, and they typically depend on the type of product or system you wish to reverse.  Reverse engineering of a product may differ from reverse engineering of a system such as that for computer software and coding.  However, the process can generalized as five steps.

The five steps of reverse engineering, which can be performed out of order or revisited if necessary.  (Image courtesy of NNDS.)

The first step is to determine the purpose of the product or system.  At this point, you will need to determine how to approach the reversing process, what will need to be researched, and what types of tests you will need to run.  You will also need to list design goals that the original designers may have had, the constraints they had, and the type of market they designed for.  Note that you need to document each step.

The second step is to observe and develop ideas of how the product or system works.  You may speculate on how it works, how it may match the original design goals, and why the designer ended up designing the way it is.  If parts, mechanisms, or codes are not visible, you may also predict what you will encounter when it is taken apart.

The third step is to disassemble the product, which should be done very carefully.  Documentation is crucial at this step and requires detailed written and even visual records.  Each component should be examined to determine why it was included, what its function is, how it was made or assembled, and how it relates to the other components.  For example, if it is a part, an engineer would ask, “How does it move in relationship to other parts?”  If it is a code or instruction, ask, “Where it occurs, is it before or after other codes?”

The fourth step is to analyze each component and thoroughly examine and investigate it.  This examination includes an analysis of function (what is does) and structure (why it is where it is).  For product analysis, measurements, material types, material properties, and how each part was manufactured are also significant to understanding overall designs and concepts.

Companies may use reverse engineering to make replicas of older parts for restoration, such as for older cars or other collectibles.  This engineer has created a prototype of an engine part.  (Photo courtesy of NASA.)

The fifth step is to accumulate all information into a single source.  This amassing of facts and data may be done as a report to provide documentation for information that was missing.  It may be used to recreate the original design.  It may also be used to help with a redesign or innovation of a new product or system.  Note that you can return to earlier steps anywhere in the process, depending on the information you encounter.

Do you have a household item that is no longer functional?  You may want to spend some time reverse-engineering it.  Carefully follow the steps above, documenting each one in your journal.  Can you determine why the product failed?  Do you have suggestions for redesigning the product?

RE Examples

Reverse engineering has helped with product and system innovation.  It can be used to determine functions and operation of historical devices.  It can also help engineers and manufacturers decrease the time it takes to develop new products and systems and get them into the market ahead of their competitors.  A lot of industries use reverse engineering, including software engineering, chemicals, electronics, automotive engineering, aerospace, consumer and sporting goods, and entertainment.  Below are several examples of reverse engineering.

Manufacturers now use reverse engineering to develop products faster.  For example, products that have irregular shapes or specialized shapes being designed more ergonomically can be difficult to produce.  Designers first develop models out of clay or other easily shaped materials and then reverse-engineer the shape.  They can use dimension inspection lasers to develop detailed computerized models of the product.  This 3-D model can then be used to develop CAD drawings and becomes the source of code for the machines that will develop the molds or direct product.  This process can also be used to develop a profile of existing parts, helping manufacturers recreate older or obsolete parts.

Dimension inspection lasers can be used to record and store the size and shape of models or prototypes, allowing manufacturers to shorten the time for tooling and production of products.  (Image courtesy of CERN, published at WikiMedia Commons and used under the following license.)

Software can also be redesigned using reverse engineering.  This can be done to locate flaws or change design goals for existing software or to allow companies to develop software to compete in the market.  In the 1980s, a company wanted to develop software to run IBM computers, which already had their own.  They used a system to avoid copying IBM’s patented software whereby one group reverse-engineered the software and provided part of their documentation (Step 5 above) to a second group.  The second group received information only on what the software needed to do and created unique software using a different method.

A reverse engineering process called "clean room" can be used to develop new but different products or systems for competition.  In this process, one person or group takes a device apart and describes what it does in as much detail as possible and at a higher level of abstraction than the specific code.  That description is then given to another group or person who has absolutely no knowledge of the specific device in question.  This second party then builds a new device based on the description.  The end result is a new device that works identically to the original but was created without any possibility of specifically copying the original.  (Image courtesy of NNDS.)

To read more about the software development above, the ethics involved, and how companies try to block this process, click here.

The aerospace industry provides another example of reverse engineering.  In the early part of this century, Boeing used reverse engineering extensively to develop the Boeing 777 airliner.  The company also used this process to scan, digitize, and produce a 747 wing in one day as a challenge to this new approach.  A total of 238 design teams used reverse engineering techniques to design their specific parts or systems, which could then be compared to and integrated easily with the other teams’ components.  Many parts from older planes and jets still require replacement, as they are still in service.  The industry uses reverse engineering to develop the information and tooling to make the new parts and to design them with much better precision than the original.  The next step is to use reverse engineering in the inspection of parts for quality control, which is currently the slowest part of design and production.

The Boeing 777 was the first airplane to be digitally designed and assembled on a computer to reduce design time and enhance the accuracy of the design.  (Photo courtesy of Solitude, published at WikiMedia Commons and used under the following license.)

Biotechnology systems also use reverse engineering.  Microorganisms can have their DNA reverse-engineered to produce new strains for the development of antibiotics and other health products.  Another area of biotechnology that is gaining due to reverse engineering is simulating the brain.  Earlier efforts in developing artificial intelligence, or machines that can think and reason like humans do, did not examine our brains in detail.  Scientists and biomedical engineers are now trying to reverse-engineer our brains to develop more sophisticated artificial intelligence devices, software, and machines.  Success in this field could be used to develop speech recognition devices, devices to restore hearing or sight losses, and computers that can manipulate information at much greater speeds.

Click here to read more about reverse engineering the brain and get more examples of how this can be used.

Click here to review reverse engineering and test your knowledge.

Additional examples of reverse engineering can be investigated.  Civil engineers use this process to recreate successful bridges or buildings to control the possibility of a failure.  Chemical engineers may use this process to develop new chemicals to avoid violating patent laws.  Electronic and mechanical devices can be reverse-engineered to help innovate and invent new products and systems.  Many times, reverse engineering is also used with concurrent engineering practice, which is the subject of the next lesson.

Item Assignments
  • Record key terms and their definitions in your journal.
  • Complete all Enrichment and Reinforcement activities.
  • Complete the Unit 3 Lesson 7 graded assessment.

Assessment not available in sample lesson