What is a boundary (part 2)?
In this post, I gave a working definition of a boundary. That definition was "a boundary is any criteria by which I factor my model of what I'm testing."
James Bach challenged me to come up with three specific examples and to tell him how they are boundaries. With that, I pulled out my moleskin and drew three different models: a UCML model, a system diagram, and the model I used to test the time-clock application.
I quickly came up with a list of 16 factors based on those three models. It became apparent to me that only 5 of those sixteen factors was a boundary. So much for that definition.
As I looked over the list I tried to figure out what was unique about the actual boundaries I identified. Then I thought about something Julian Harty once said to me about boundary testing. He asked the question, "do all boundaries have a quantifiable component?" (Or it was close to that in my memory. If I misquoted him, he'll let me know and I'll update the post.)
When he asked that, I immediately said no. He then asked me for an example, and I struggled to find one. At WHET #4, Rob Sabourin gave a beautiful example of boundary bugs from an experience testing Arabic to Latin text conversion. So I still think it's no, and I now have an example. However, it's still an excellent question, and remembering it gave me an insight to my working definition.
I have a new working definition:
"A boundary is any manipulatable criteria used to factor the model I'm using for the product I'm testing."
In the definition above, manipulatable means I can change it and it means I can measure/monitor it. Using that definition, when I went aback to the factors I identified from my three models, I was able to include those I felt were boundaries.
(At some point, if I think of it, I'll scan and post the moleskin pages.)
James Bach challenged me to come up with three specific examples and to tell him how they are boundaries. With that, I pulled out my moleskin and drew three different models: a UCML model, a system diagram, and the model I used to test the time-clock application.
I quickly came up with a list of 16 factors based on those three models. It became apparent to me that only 5 of those sixteen factors was a boundary. So much for that definition.
As I looked over the list I tried to figure out what was unique about the actual boundaries I identified. Then I thought about something Julian Harty once said to me about boundary testing. He asked the question, "do all boundaries have a quantifiable component?" (Or it was close to that in my memory. If I misquoted him, he'll let me know and I'll update the post.)
When he asked that, I immediately said no. He then asked me for an example, and I struggled to find one. At WHET #4, Rob Sabourin gave a beautiful example of boundary bugs from an experience testing Arabic to Latin text conversion. So I still think it's no, and I now have an example. However, it's still an excellent question, and remembering it gave me an insight to my working definition.
I have a new working definition:
"A boundary is any manipulatable criteria used to factor the model I'm using for the product I'm testing."
In the definition above, manipulatable means I can change it and it means I can measure/monitor it. Using that definition, when I went aback to the factors I identified from my three models, I was able to include those I felt were boundaries.
(At some point, if I think of it, I'll scan and post the moleskin pages.)