We have seen the demos. Can we watch one whole job?

A finance director I work with would not sign off a finance build last week. He had sat through demos of every part of it over several months. What he had never seen, not once, was one job going in at one end and coming out the other, on the actual system, in one sitting. He was right to hold out, and I should have offered it before he asked.

What he actually said

His words, more or less, were that he had seen bits of it working in demos, and that was true, but it was a long time ago and lots of things had happened since. Then the part that landed:

I just haven't seen one run start to finish, from quote through to the final thing, live on any system. I've never seen that on anything.

And underneath it, the real reason he was digging in: he had been criticised once before for signing off something he had not watched run. So this was not fussiness. This was a man who had been burned by exactly this gap and did not intend to be burned twice.

Why demos hide the join

A demo shows you a feature. The feature almost always works, because the person demonstrating it built it and is driving. The failures in business software are hardly ever inside a feature. They are in the joins: the quote that has to become an invoice, the invoice that has to land in the accounts with the right date on it, the part refund that has to go back out and reconcile against something. Nobody demos a join, because a join is boring and takes forty minutes to play out.

So basically a demo is a tour of the rooms. A start to finish run is walking from the front door to the back without lifting your feet off the floor. They are not the same proof, and it is the second one you are putting your name to.

The fair objection, and the way round it

The developer on that call pushed back, and the pushback was reasonable. Running a full dummy job through the live system puts fake data into your real accounts, and someone has to go and unpick it afterwards. Fine. Then do it on a copy of the system with data shaped like yours, in one go, with the client's hands on the keyboard rather than mine, and record it while it happens.

Record it because sign-off has a shelf life. Months pass, twenty small fixes land, two people leave, and nobody can honestly remember what they watched. A recording settles that argument in four minutes instead of two meetings.

• the job created the way your own team would create it, not the tidy way
• the money step, including the awkward ones, part refunds and credits and the rest
• one thing broken on purpose, so you can see what the system does when it is wrong
• a person who does the job every day driving it, not the person who built it
• the whole thing recorded, with the date on it

If you are buying software, make the start to finish run a condition of sign-off, and schedule it before the last payment rather than after. If you are selling it, offer it before anyone asks, because the person who has to put their name to the thing is usually the person who has seen the least of it.