The Eighty – Twenty Percent Rule

First up, apologies in advance but posting will be light this week. I’ve managed to write every workday this year, but my family are visiting from England and I’ll concentrate on spending time with them for a few days.

I thought I’d share with you a quick rule-of-thumb that I’ve stated to use to help clients who are new to the Open Source World. I call it the 80% / 20% Rule.

What’s the 80% / 20% Rule?

I think its a really useful way of helping people understand how fundamentally different development in the Open Source world can be from custom-coded sites.

80% of the work on most Joomla sites can be done in 20% of the time it would take to build the site with custom code. However, that last 20% of changes can take 80% of the project time.

Previously the Lifecycle of a Project Would Be Like This:

  • Week One / Two: Wow – you got all that done in 5 days! I’m so, so glad we chose Joomla.
  • Week Three / Four: Ok. things are still ahead of schedule.
  • Week Five / Six: Mmmm…. It took you that long to make the component change its behavior ?!? I guess the deadline was about right after all.

A Simple Example From Last Week:

A client wanted a complex form recreated in Joomla. They estimated it would take a days work to hardcode. We had it ready in less than an hour. The stickler came when they wanted the form to look like a PSD they’d created and we needed to hack the code for another four hours to achieve some relatively minor layout changes: 80% of the work was done in an hour … the final 20% took four hours.


I’ve taken to talking about the rule upfront with clients to help them get realistic expectations about a  project’s progress. Hopefully it helps them understand the bursts of speed and sudden plateaus we face when building Joomla sites.

Leave a Reply

Your email address will not be published. Required fields are marked *