In the real world…
Two weeks ago I moved house. I, obviously, needed to pack up my room. To do this task I had estimated both the time it would take and the amount of transportable storage I would need. I decided I could perform the task over three evenings, first packing the electrical devices, then some odd bits and bobs I had lying around and lastly, I would pack clothes. I had three big cardboard boxes, two large suitcases as well as a couple of rucksacks.
The good news was, I fit all of my stuff into the storage I had. Admittedly with some squashing of suitcases and some overflowing boxes – but I did it!!
Unfortunately, the time I allotted myself was nowhere near enough and I ended up packing until the early hours in the morning before I moved – but, hey, we all do overtime every now and then.
Even more unfortunate for me was that this move did not work out from the get go, and I’m now sat here surrounded by half-packed stuff – ready to move again. Joy.
The Educated Guess
Now that I’m packing again I felt this time I knew exactly how long it would take and what level of storage I would need. I had exactly the same amount of stuff as before and knew where everything was, easy!
Sadly, incorrect! The packing took even longer. I guess the stress of the double-move had a negative effect on my motivation for the task (I guess that’s why I’m sat writing this & not packing!). Also the boxes & suitcases etc that I had did not suffice and I had acquire another large box and another bag. How annoying!
So, what am i getting at?
In the software world most people estimate and size our work items before doing them, usually this leads us committing to do a task in this time. If we relate this way of working back to my real-world moving example…
On the first move the perception would be that I “succeeded”. All of the stuff that needed to be moved, appeared to be moved. Awesome. Except:
- I crammed so much stuff into my suitcase that its broke the zip opening it. doh!
- My boxes we so full that stuff fell out when carrying it – and I still can’t find my computer mouse…
- I stayed up so late that move day was a real slog.
So, from this I would like to draw your attention to the dangers of doing anything (and at any cost) to stick to your estimate. That missing computer mouse could be a very damaging bug you overlook. Not only that, I “worked overtime” to get the job done. This caused a huge detriment to my ability on the following day – if moving was my day job i certainly wouldn’t be able to keep this up every week.
Second-time around is worse, I’ve already underestimated both the time and the storage I need. What’s the reason for this? Simple, this task [despite appearances] is not the same as the last one. First I have changed – lets face it moving twice in a fortnight is not a small amount of stress and no matter the task motivation is key. Secondly, the task itself is different. Okay, I’m moving the same stuff, but everything has a different place to be before. This is the same when writing software, no two tasks are the same, sure you can draw similarities but ultimately you’re just guessing again – and just because one task is similar to another you can still be wildly far off your estimate.