It’s not about the Feature, it’s about the Scenario!
I just came back from South Africa where Arvindra, Ingo and myself delivered the Architect Forum on Software Factories in Johannesburg, Durban and Cape Town. Since the Cape Town event was on Friday, we stayed over the weekend to explore the great landscape of the Capes.
While Ingo and I were visiting the area of “Cape Point” and “Cape of Good Hope” I got attracted by the following historical actuality:
As we all know, sailing along the coast of South Africa was a big challenge in the early days of our global economy. A lot of ships crashed on riffs which surround the capes. In the mid of the 19 century, the plan emerged to build a lighthouse that helps ships to navigate around the cliffs of “Cape of Good Hope” and “Cape Point”. The big question was where to place the lighthouse:
- On Cape of Good Hope, the most south-western point of the African continent
- On Dias Point, close to the actual riffs
- On Cape Point, 249 meter high peak between Cape of Good Hope and Dias Point
They decided to build it on Cape Point because it can be seen from far away. The lighthouse was built in 1860 and the white flashing light of 2000 candlepower could be seen by ships 67 kilometers out of sea! From an engineering perspective, this was great work. But in reality, the lighthouse proved to be ineffective as it was often covered by cloud and mist. At this point one important question arises. The scenario that makes a lighthouse most valuable is navigating in bad weather and poor visibility. By solely focusing on the candlepower and the ability to be seen as far as possible, the decision to build the lighthouse on the highest point sounded brilliant. In reality, it was very ineffective as it didn’t support the most important scenario: navigating in bad conditions! After the wreck of the Portuguese liner “Lusitania” in 1911, it was decided to erect a new lighthouse on Dias Point, 87m above sea level.
I think this is a great example why scenario driven design approaches makes so much sense and can prevent our systems from great but useless features!