The Product Development Process – Step 2 – Requirements

The Product Development Process

Product Requirements and Engineering Specification

Product Requirements
&
Engineering Specification

Step 2  –  Defining Product Requirements

After the “Bright Idea”, the next step is a “List” of product requirements attributes, and goals.  The “List” (known by many names) is really the Product Requirements Document or Engineering Specification.  Are those titles too sophisticated?  Maybe, but it’s a necessary document — as a guide for the process.  Referring back to this engineering specification will keep you on track and out of the weeds.

Below, is a collections of things to consider.  It’s long, but plow through it. It’s important.  While not all items apply to every product, each should be considered.

Note:  A definitive list of requirements is not necessary to begin the process because the list will be refined as you go.  However, the better the engineering specification at the beginning, the easier it is to complete the next steps — without backing up and wasting both time and money.

The Best Use Of This List

Copy these questions, and write an answer for every one.  Additionally, write down everything else that pops in your mind while you’re doing this.  The more complete you make the list, the better it is later.

After making lists of product requirements you can format the information into an engineering specification. Compile and format the new document in any way that works for you.  Just realize the new document will grow over time as you learn more, and you will refer back to it often.

Considerations for Product Definition:
  1. Who will use the product?  (Is it the end customer?)  Who will buy the product (the “real” or “buying” customer)?  Notice the very important difference.  Sometimes they are the same, sometimes not.
    For example, think of a widget made for a hotel.  The “buying” customer is the hotel purchasing agent.  The end user may be the staff or the hotel guest.  It does not matter what the staff may want if you can’t convince the purchasing agent to buy it.

    Understanding the customer(s), all of them, is important for success in both design and marketing.

  2. What are the customer’s requirements?  Consider life span, product function, strength, rigidity, flexibility, product look, feel and performance.  Consider complementary products and how their changes will affect your product.
    A widget made for use in a car, for instance, may not work in all cars and its usefulness may diminish with the next model year.
  3. How much will the product cost?  It is important to know how much a customer will pay for the product because it must be produced for much less.  Typically, a product on the shelf is manufactured for 1/4 to 1/6 of the price you pay because of mark-up and margins required by all the people that handle it.  Additionally, when making the requirements list, there should be a specific cost goal — like less than $5.  It is not enough to say “make it “make it as cheap as possible.  The specific goal is the input needed.  (The goal may change as you learn more, but it must remain specific.)
    One important note with respect to cost:  Cost and price are two different things, and a good business plan will make the most of price without regard to cost.  The discussion above is specifically to make sure your cost (& appropriate markups) don’t exceed your customers desire to purchase.
  4. How many widgets are expected to be sold, and in what time frame?  The quantity to be sold will drastically effect the cost of the product, and what processes are used to produce it.
    Quantity is King with respect to cost.  Almost always, the more you make, the cheaper each piece is.
  5. How will the product be sold?  At Walmart?  Or through a distributor?  In Magazines?  Or through TV advertisement?  Will it be sold whole?  Or will it be assembled by the customer?  How will it be packaged?  All these things effect both the cost and the design in many ways.
  6. What is the timing?  Some products are time sensitive.
    A toy, for instance may need to be on the shelf in October to sell for Christmas.
  7. What is the expected life of the product?  Will this product sell successfully for many years?  Or will it sell like wildfire for just one season?
  8. How will the item be marketed?  Items to consider include:  Presentation, Weight, Packaging, Shipping, Colors, Sizes, etc..
  9. Usability — often forgotten — includes how the product with interact with those who will use it.  There is a whole field of Human Factors or Industrial Design that deals with how products interface with humans.
    You’ve probably used products that fail the “Intuitive Test” (my words for “Can I figure out how it works?”).  Those are the things people complain about, and you don’t want yours to be like that.
  10. What is the expected use? — and perhaps more important, what is the expected misuse or abuse?  How can the product be made to accommodate these expected situations?
  11. What product safety issues are involved?  Are there safety concerns with misuse?  In what ways is it possible for the product to fail?  And what are the consequences?
    This area of study is often referred to as FMEA or Failure Mode and Effects Analysis.  All potential failure modes MUST be considered carefully — and documented — especially in our demented, sue-happy society.

    Some of this discussion on product safety leads to additional questions like What kinds of Product Liability Insurance will you need?  Take some time and think these issues through.

  12. What are the hard points of the “Bright Idea”?  Identify the points that cannot change?  What areas can change if needed to better meet other, more important requirements?Product Design and Engineering are sometimes referred to as “The arts of trade-off’s”.  Give a little here, take a little there as a balance in optimizing the product requirements.
    For example, gold is the best electrical conductor, but the price of gold usually does not fit in cost requirements.  The trade-off is to use a different material that also conducts well, but costs much less.
  13. Will a warranty be provided?  If so, what will it cover and how will it be handled?
  14. What governmental regulations or certification requirements must be met?  This will depending on the product and how (or where) it is to be sold.  It may also be dictated by your industry.  Certifications like CE or UL (or some other) may be required.  OR, certain standards like ANSI may be required.  Look carefully into what or who governs the use of the product.
  15. Are there legal concerns like patent infringement, or intellectual liability issues?
    Note:  If you see that your product will have legal concerns, address them up front, and carefully document what you do about it.  Get professional help where needed.  Inventors often look at patents and such, but not at risks or exposure.  Don’t let it stop you, just do the homework.
  16. Will the product have social concerns like disposability or recyclability?
  17. Some thought must be given to manufacturing issues like cost, time, material, size, weight, complexity, where it will be made, etc..  Government regulations may limit these choices — like material properties.  (These issues are addressed in depth in the design process, but a good feel for what is expected up front is helpful and should be in your engineering specification.)
  18. Where will the product be made?  Though this question really should not be answered prior to looking at things like “how many” and “what processes”, please identify how you feel about ON SHORE and OFF SHORE manufacturing.  Knowing how you feel about different areas of the world such as Mexico, Indonesia or China is important.
    Note:  There has been a trend in recent years (especially in the USA) to farm out all sorts of manufacturing to low cost producers of the world such as Mexico or China.  Some companies do this quite successfully, others struggle.  It is our experience that manufacturing overseas requires a lot of hand-holding and the costs to do so are very often forgotten.  More about this later.
The Requirements  (our Speaker Example):

In our example of the stereo speakers, the product requirements list included the following (as well as many others):

  • Sound quality is Most important — the speakers must perform as good or better than other high-end products or it wouldn’t be worth the effort.
  • Performance characteristics like frequency response, high and low end fall-off, flatness of the performance curve, efficiency, power levels, etc. are used to quantify “Sound Quality”.
  • In addition, performance characteristics drive other requirements like stiffness, porting, etc..
  • Product size, look and presentation  (This requirement changed through the design process.  At first a typical rectangular box was expected, but engineering suggested something better — and form followed function — to produce a unique, and smart shape.)
  • Ease of construction – this requirement limited the possibilities for construction and therefore limited the design to something that can be built with typically available equipment and skill.
  • Complimentary product – could or should a sub-woofer be suggested?
  • And many, many others.

Of course, for compactness, these are just a few key points from the Engineering Specification.

Concluding Thoughts . . .

The Product Requirements stage of the process is often skipped or skimped early on.  It’s a mistake that often results in delays, backing up, higher cost and a longer time to completion — because some things have to be revisited when something is missed.

From a Product Development standpoint, defining what is “required” is one of the most important steps, and it will be done, one way or another, like it or not — on purpose, or by accident — before the product is finished.  The way you do it, and when you do it will certainly influence the final outcome.

My suggestion?  Do it early, and be as complete as possible, then revise as necessary.  It will streamline your processes and save a lot of headache.

Finally, having a proper engineering specification in hand is the best way to document your design if your intentions are to sell, license or patent the end product.  It’s also a great way to show potential investors that you know the product requirements and therefore know what you’re doing and where you’re going.


Continue Product DesignNext Up:  Step 3  –  Info & Planning

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The Product Development Process