I am coming to Visio from a standing start, but am very familiar with other MS Office tools and quite happy in Excel and Access. I don't have VBA skills though.

I am trying to build a flow chart that will do some simple calculations. I can fathom how to build the 'picture' of the chart, and can see where I can add data to the boxes and have worked out how to add a new data field and type, but could do with a shunt in the right direction as to how to add in simple mathematical links between the boxes - even a link to an online 'how to' would be useful,. I have searched and searched the net and cannot find the seemingly simple thing I'm after.

I am setting up a fairly complex flow diagram to how how various contributing operations link together into a final whole operation. I want to track data relating to each operation, for example kW of electricity. So for the office operation, I might have 4 boxes linked to/feeding the 'Office' box, say: computers, light bulb 1, light bulb 2 and air conditioning. I've made a field to hold a value for the kW of electricity in each box.

Where and how (syntax would be great) can I implement a calculation that will show total electricity consumed by the office, i.e. the sum of computers, light bulb 1, light bulb 2 and air conditioning. I assumed I could put the calculation into the office kW field, i.e. the equivalent of Office kW=(computers;kW)+(light bulb 1;kW)+(light bulb 2;kW)+(air conditioning;kW), however it doesn't seem that simple.

My aim is to produce a finished flow diagram that perhaps tracks several values, maybe water consumption, electricity use, waste generation and then be able to see how varying values in one area changes the values in another.

The complexity of Visio seems to provide the possibility of doing this, but I need this confirmed and could do with some brief instructions (or where to find them) to get started (I'm a quick study and a shove in the right direction would be great). To begin with the basic maths would be useful, I can revisit niceties like changing the colour of the boxes with the values later.

If Visio isn't the tool to do this that would also be useful to know and I'll run it up in Excel, but I can't believe that Visio wasn't built for this.

Many thanks