Now that your design problem has been clearly defined and the specifications have been set out, it is time to concentrate on thinking of solutions. When there is an existing solution to your problem or a similar one there are three basic types of design ideas that you may generate: scaled designs, evolutionary designs or revolutionary designs. A scaled design can be derived from an existing design that does the job well, and just needs to be scaled for your application. An evolutionary design can be created when an existing design is pretty good, but fundamental improvements can be made. A revolutionary design is a totally new approach used to achieve the same function as an existing design, but with better performance. All three approaches can have successful results. In fact, your final design will probably be a combination of all of them.
Begin by generating ideas on your own (you may have already done a little of this while you were doing research into the problem definition). Try to think of as many different ways as possible to solve the problem. Be sure that you do not focus on a single approach. Use sketches and notes in your design notebook to record your ideas. Be sure to use large, well-labeled sketches so that others will be able to understand them. Some ideas will be at the system level and others at a more detailed level. Keep track of them all. Think of at least ten ideas for your project and record them in your design notebook. They may be ideas for the overall system or for the sub-systems. Use these ideas as a starting point in your group idea generation session.
As a team, you will have a group brainstorming session, chose one or two people to record information. Before you start, be sure that you agree on the problem, and state it clearly. Each person should have a packet of sticky notes, and as you come up with new ideas, write them down and add them to the work surface (wall, table, floor, or whatever is comfortable for you). This allows you to capture your ideas as they come in without interrupting others. You should start by giving each team member the opportunity to share an idea from their individual list. Build off each idea as it is presented, and see where that goes. New ideas will emerge, don't pass judgment at this point, and encourage all new ideas. You will evaluate and critique ideas at a later stage. In order to ensure a productive brainstorming session, keep it under one hour, and follow the Rules of Brainstorming (it is highly recommended that you put them up on one of the walls where you are meeting or on a whiteboard):
Once you feel like have exhausted your ideas, try to generate more. One way to do this is through a process called bisociation. In this approach, you choose a topic that may seem unrelated to your topic, and then think of ideas that bring these two ideas together. For example, you may be generating ideas for the charcoal project, and choose the bisociation topic of shoes. Then you might think of how you could use shoes as a material to make the press, how a shoe could operate the press, how the shape of the shoe could be incorporated into the press design, how shoe manufacturing methods could be adapted to make charcoal, how charcoal could be used in making shoes, or how it might be used to absorb odors in shoes. And then you might decide to follow up on one of the more promising ideas. How charcoal might absorb odors, or perhaps other contaminants, perhaps chemicals in water, perhaps removing pesticides from ground water, and perhaps the charcoal could be formed into a briquettes in a way that you could regulate the pore size, and then it could filter bacteria from the water as well. Which leaves you with the idea of making charcoal water filters for removing chemical and bacterial contaminants. Which might actually be a good idea (let's go make one and try it out!!!). You may choose to do bisociation with additional topics if you don't get fruitful results from the first.
There are many strategies for creative idea generation, brainstorming and bisociation are just a couple.
At the end of your session, group your ideas together into similar approaches and write up a brief summary of each approach. As a team, choose five to ten approaches that you think are worth following up on.
The results of your idea generation sessions should be summarized and presented at the Ses #13 design review.
Now that you have sorted through your ideas, you will need to start the process of choosing the best approach. It is often necessary to investigate the approach further in order to make that decision. Go through each approach and think of the key things that you would need to know in order to effectively evaluate the approach. Think of simple experiments that you could do to find out this information if it is not possible to get the information through additional research or through analysis. Devise an experimental procedure, and perform the tests to get the information you need. At this stage, you need to go fast, build mock-ups quickly and cheaply that will provide you with the results you need. Don't waste time on complicated concepts at this stage, and don't sweat the details.
Each team should present the results of the research, analysis and experiments for each approach at the Ses #13 design review.
Your next task is to choose which of your many ideas you will concentrate on in your design solution. It is often difficult to do this as ideas tend to take on a life of their own and you will find that you each have favorites. It is important to judge as objectively as possible. You will need to consolidate your various ideas into designs that you can compare. You might consider group together ideas that are similar and combine them into a single solution. Try to narrow it down to three to five different concepts, each of which may be a marriage between several of your original ideas.
A Pugh chart is a tool that helps evaluate ideas by setting up a list of characteristics and judging each idea in terms of the individual criteria. This helps to create a more objective and structured selection process.
One idea is chosen as the datum, or the idea to which all others will be compared. It is a good approach to choose a fairly simple idea as the datum, as it will be easier to do the comparisons than if you choose one of your more complicated ideas. Revisit your problem statement and your list of design specifications to determine the criteria and characteristics that you will use to judge your potential solutions. For each of the criteria, decide if the option you are evaluating is the same (0), better (+) or worse (-) than your datum. Tally the results for each option and determine which idea is the best. You may want to weight some of the criteria more heavily (for example, safety might be deemed more important than portability when evaluating your idea, and therefore you may choose to double the weight of that criterion). You may also find that when you make your final selection, you will choose characteristics from several of your options and combine them to form the final design; however you should be careful not to make your project too complex.
Each team should present the results of their concept evaluation at the Ses #13 design review.