The Yes, The No and the Painful: using, and failing to use, estimates for a no-go decision

@AgileKateOneal recently asked for examples of effective estimate use in medium/long-term planning.

Example 1: Back-of-the-envelope Go/No-Go Decisions

Making a no-go decision sprang instantly to mind. Many such decisions are casual and quickly forgotten: the back of an envelope calculation which says that an idea is well beyond what we can afford; and the conversation moves on. But that estimate may have saved you from months of wasted effort.

An NoEstimator might object that one could profitably try out something rather than nothing. Which is sometimes true, but creative thinkers in commerce & IT can always generate a hundred more ideas than a team can try out. You can't try out everything.

Example 2: Small UK charity looking at CRM options

in November last year I worked with a small UK charity, www.redinternational.org who were badly in need of some kind of CRM software to keep in touch with supporters and project partners. They were running largely on spreadsheets built from downloaded reports from virginmoneygiving.com / mydonate.bt.com etc. They also had an Access database with a fair amount of donor & similar data in it.

Question: Is it better to pay for a CRM solution — typical charity starting price £10,000 going up to easily £100k – or get someone to do enough work on the Access database to make it a usable solution?
My Answer: I first spent some time discovering and documenting their main use-cases (to clarify: their 'business' use cases, that is the things the charity had to do whether manually or with IT). I gave that picture to the CRM providers so that they could give us a sensible proposal. And I worked out an estimate for extending/developing the Access database. Based on that, we could see that a CRM consultancy/solution looked like £10-£20k (5 year cost) and the DIY-option about 200-400 developer days.

Even with this level of accuracy it was good enough to see that DIY should be a no-go. I did not expect this. I thought that the charity's actual requirements were sufficiently small that we could do something useful for a few thousand pounds. But two hours spend going through their use-cases on my estimating spreadsheet showed me that I was wrong. So, I recommended the best value CRM option.

This, I think, is planning 101: a couple of hours working through the detail on paper is a lot cheaper than running the experiment; but can be enough to make a probably-good decision.

Example 3: Provide a system to automate a small team's manual processes for a capped price

This was for a financial services company in 2013. The team were working on PPI claims for an insolvency practitioner (obliged to pursue potential claims that might bring in some money for their clients' accounts) and had about ten thousand potential claims with hundreds per month being added. They had been working manually on spreadsheets for over a year.

I spent 4 days on analysis and listed a set of use-cases that covered the processes end-to-end; and I estimated that a suitable system could be done for about 40 days development work. The estimate cost about 3 or 4 hours on top of the analysis.

The contract to provide was capped-price. The customer was not open to a no-estimates approach. And I accepted being bargained down to below my estimate (Doh! I hear you say. Quite so). The actual cost came out close to (but above) my original estimate, but could have used another week's work to make it user-friendlier.

The better course would have been to use the estimate/budget mismatch to declare a no-go rather than accept a reduced budget. This might have resulted in the client agreeing to go ahead anyway (which might in turn have led to a no-estimates approach to the work). Or it might have led to no contract. Either way would have been less painful and more controlled than over-running the budget.

The Yes, The No and the Painful: using, …

by Chris F Carroll read it in 3 min
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