Christensen talked about the tendency for products (or services) to start off simple, cheap, and convenient. Over time as technological change proceeds, the products become more sophisticated. Only a few skilled people can use the product; it’s used in a centralized place. Finally, innovation comes full circle, making the product simpler and more accessible again.
Christensen recounted a history of computation to illustrate the concept and used concentric circles to indicate the number of people served by each innovation. We started with the slide rule. Because it was easy to use, cheap, and convenient, virtually everyone in the sciences at university had one. Early computers – although a huge advance in capability - lived in centralized ‘glass houses’ tended by highly trained acolytes and accessible only to those few people. Early computers were not easy to use, they were not cheap, and they were not convenient. Eventually, mini-computers and PCs punched through the glass walls and brought computers to less skilled people, and a much broader audience. And now, the iPad, iPhone and other mobile devices have completed the decentralization cycle – they’re easy to use, cheap and convenient, and they’re accessible to virtually everyone. In fact, even more people use these devices than ever used slide rules.
Maybe some readers of this post will remember the days of doctors’ house calls. This was highly convenient for patients and very accessible – call a doctor in the morning and he’d drop by in the afternoon! With advances in medical knowledge, the practice of medicine withdrew to specialized places, like the big research and teaching hospitals, where patients are treated by highly skilled doctors working in ever narrower specialities. So, healthcare is now at the stage of the ‘glass house’ – it’s not easy to access, it’s not cheap, and it’s not convenient. The next big improvement must be to decentralize the practice of medicine.
In other work, Christensen has described corners of the healthcare industry have already undergone such decentralization. Minute Clinics is an example of this decentralization process. In Minute Clinics, situated in drug stores or grocery stores, nurse practitioners treat a limited number of conditions. Thus the service is being carried out by nurse practitioners, with lower skill levels than doctors. The service is accessible, cheap and convenient.
There's a more extreme example in diabestes treatment. In the ‘old days’, back in the 70’s, diabetes patients had to trek to a doctor’s office to have blood drawn and sent to a lab for analysis. Results were outdated by the time they got back to the patient. Thus the testing process was expensive, required specialized doctors and lab technicians, and was certainly not convenient. In contrast, the advent of self-monitoring kits has decentralized diabetes treatment, rendering it accessible, cheap and convenient, as well as better quality. And it represents the ultimate in low skill use - patients themselves.
Christensen argues that this migration of medical treatment to lesser skilled people (ultimately self-treatment like the case of diabetes), in more convenient locations will deliver better healthcare at a lower cost. This was a challenging proposition, when you consider that he was speaking to the Ontario Hospital Association!
 I remember that period well. I worked at a timesharing company called I.P. Sharp Associates and one of our main attractions was providing users with an end-run around the impenetrable barrier of the computer centre.
 Admittedly, cost barriers made this kind of convenient, accessible service unavailable to some.