Testing a bridge – part I. – testing the requirements

Not so long ago my brother organised a weekend retreat and since most of his friends together with him are civil engineers, he came up with the idea of building a bridge out of pallets that we got from my mother’s workplace.

He then quickly wrote up a draft about the requirements and a detailed drawing about his first idea. I instantly thought that this should be the other way around.

Here are the requirements and my attempt to make them clearer:

We are building a bridge:
– in the garden
– out of pallets
– wing-spread: 5,5m (later: new info on pallets, we have to reduce this)
– 20 identical pallets (later: there is only 16 pieces)
– pallets are free
– they are so-called “block pallets”
– 1 kilo 100mm nail
– 1 kilo 65mm nail
– 10 m rope
If done 6 person has to walk over it.

I hope your brain got going just like mine when reading this. I spent an hour brainstorming on this and came up with a critique of the requirements.

– We are building a bridge
Who is going to use this bridge? Is it important that children, older ones, handicapped, blind or people with crutch could use it?
For what this bridge is going to be used? From where to where will it go? What will it bridge?
What weather conditions it has to withstand? Think about the wood, the rope, the nails.
If the bridge has to be dismounted later, is there a plan for that? What’s that like? Maybe that should be considered while planning.
If the bridge will stay, will it be easy to move it around if necessary?
Is there any requirement about it’s weight?
Is there a similar team that has built a similar bridge, with similar equipments and requirements? Can or should we talk to them?

– In the garden
What’s the soil like there? How is the weather?

– Wing-spread: 5,5m (later: new info on pallets, we have to reduce this)
Is there a maximum or minimum to the wingspread?
If we have to reduce, with how much exactly? (will that be a minimum? or a maximum?)
Is there anything else required regarding the size?

– 20 identical pallets (info later: there is only 16 pieces)
When can we verify that they are indentical? Is that important?
Can we expect these requirements change again?

– Pallets are free
Could this be a problem? Maybe they tell us something about their quality?

– They are so-called “block pallets”
What does this mean? Is it important? What other types are there?

– 1 kilo 100mm nail and 1 kilo 65mm nail
Would it make more sense to list this requirement in number of pieces?

– Once ready..
Maybe we should try it already as soon as it’s possible before it’s ready

– If done 6 person has walk over it.
6 people? What people? Maybe this requirement should be given in kilos?

There were some people who didn’t really understand why I wrote all this up, some people understood where is testing in here.