Reading a Structure Diagram

Reading a structure diagram means explaining, for each box, what that part of the problem does and which smaller tasks it is made of, then following the lines to see how the parts depend on each other. The diagram is a record of how the problem was broken apart, so reading it back is how you check the split makes sense.

What each box does

Each box is a task, named with a short phrase such as Book in the bike or Take payment. Everything below a box is the set of smaller tasks that box is made of, so you read a branch downwards: the parent job is carried out by doing the tasks beneath it.

For example, the top box Process a bike repair has three subsections: Book in the bike, Carry out the repair and Take payment. Under Carry out the repair sit three smaller tasks: Find the fault, Fit new parts and Test the brakes and gears. Reading those three tells you what Carry out the repair actually involves, which the single box on its own does not.

How the subsections link

Lines join a box only to its parent above, and they mean is part of, not happens next. The other thing to read is the flow of results: often one subsection produces something that another one needs.

Fit new parts cannot be understood on its own: which parts get fitted depends on the list made in Find the fault. Spotting that dependency is the point of reading the diagram, because those two subsections then have to be planned and tested as a pair.