This post is part of a special report on social innovation from What Matters, McKinsey & Company’s journal of ideas, in which innovators from around the world share their strategies.

We have well-developed tools for tackling social issues based on thoughtful analysis and technological inventiveness, but there has been something missing from the toolbox. We have not traditionally applied design thinking to this set of problems, yet design is a process especially suited to divergent thinking—the exploration of new choices and alternative solutions.

Design thinking is scalable and can be applied incrementally to improve existing ideas (such as how a service is delivered or how a product performs for the user) or it can be applied radically to create disruptive solutions that meet the needs of people in entirely new ways.

Safepoint founder Marc Koska was seeking to reduce the transmission of blood-born diseases through the reuse of syringes. He could have designed better packaging or communications to educate medical staff about the dangers of not properly disposing of used syringes. This approach might have helped in an incremental way. He chose instead to design an entirely new autodisabled syringe that breaks automatically after first use. This disruptive design has the potential to significantly reduce the more than 7 billion unsafe injections given every year.

Design thinking is accessible as an approach to innovation in a way that technical R&D is not. It can be applied by people from a broad range of backgrounds to problems ranging from creating new products and services to redesigning business processes, building new brands, and improving communications.

Design thinking is centered on innovating through the eyes of the end user and as such encourages in-the-field research that builds empathy for people, which results in deeper insights about their unmet needs. This focus helps avoid the common problem of enthusiastic “outsiders” promoting inappropriate solutions and ensures that solutions are rooted in the needs and desires of the community.

And how exactly do you go about it?

Ask a good question. The most important prerequisite to a good idea is a good question. When we face intractable social ills we are doomed to failure if we simply ask the same questions over and over again, expecting to receive different answers. The greatest entrepreneurs and creative problem solvers (social or otherwise) exhibit an ability to ask surprising and insightful questions.

Dr. G. Venkataswamy (Dr. V), founder of the remarkable Aravind Eye Care System that makes high-quality eye care accessible to low income customers, asked the question, “Why can’t the principles of McDonald’s be applied to eye care?” Asking this question led him to creative ideas about efficient, high-quality care that have had untold impact on the lives of hundreds of thousands of the poor of South India.

Get close to the lives of those you are trying to serve. Understand their actual needs rather than posing a hypothesis about what they might need. All successful innovations balance the requirements of desirability (what people need), feasibility (what technology can do), and viability (what is sustainable or profitable). Design thinking starts with what is desirable, not what is feasible, in order to seek out the best opportunities to create value and impact for the user.

Build to think and launch to learn. Use prototyping, not speculation, to learn about the viability of ideas and to evolve them toward fitter solutions. Launch simple ideas early but structure to learn from these experiments and iterate the ideas quickly.

Through our work with a US-based consumer goods company, we tried to understand what people in rural Ghana would pay for in terms of health and beauty products. We asked many questions, but not until we set up a mock shop on the side of the road in a village did we understand that people would pay more for some higher-quality, branded products, such as vitamins and toothbrushes, and were reluctant to pay for others, such as detergent and toothpaste. This market knowledge allowed us to recommend a basket of goods, a pricing strategy, and a branding direction to the client, who has now effectively established a microfranchising business.

See the entire business system as a design opportunity. Products and services may be at the core of what poor people need, but often the surrounding infrastructure of distribution, communications and marketing, support services, and business models are the least well developed and offer the most potential for innovation.

In Kumasi, Ghana, we worked with Water and Sanitation for the Urban Poor to design a toilet and system around it for in-home, urban sanitation. We first designed the service and business offering, which led to the pricing, branding, and, finally, design of the product. This offering is now being tested in 100 Kumasi households, with plans to expand to 10,000 households in the near future.

Teach a person to fish… Sometimes the end solution is not the only benefit of design thinking. We have found that designing effective tools for others to design with can have significant impact. Not every nonprofit has access to designers; indeed, there are far too few designers focused on solving challenges in the social sector. To help mitigate this deficit, the Bill and Melinda Gates Foundation funded a project to create the Human-Centered Design Toolkit to act as a field guide for NGOs and non-profits looking to innovate. The toolkit has been downloaded well over 60,000 times and used to support projects such as the design of a maternal hospital in Nepal, a cooperative of weavers in Rwanda, water distribution management systems in Malawi, and hand washing stations in Vietnam.

Given the scale and diversity of social challenges facing us today, ranging from climate change to failing education systems to threatened food, water, and energy supplies, to chronic health “pandemics,” I would argue it makes sense to use every approach we have in the toolbox to seek out new solutions to improve the state of the world.

Read SSIR’s article, “Design Thinking for Social Innovation.”

Tim Brown is CEO and president of IDEO, a global design firm. Brown advises senior executives and writes extensively. His articles have appeared in Harvard Business Review and the Economist, as well as other prominent publications His book on how design thinking transforms organizations, Change by Design, was released by HarperBusiness in September 2009. An industrial designer by training, he has exhibited work at the Museum of Modern Art in New York, Axis Gallery in Tokyo, and the Design Museum in London. Brown maintains a blog on the subject of design thinking.