Archive for January, 2010

Ah, perhaps the quintessential question in a world where we are starved for time: how long will it take? It could be anything really: a project, a meeting, a visit to the dentist, picking up the kids from school, or going to the grocery store. Working in software, I continually have to answer this question when asked how long it will take to release the next version, implement a new feature, or fix a bug. However, budgeting our time affects our personal lives as much as it might our professional lives.

Over the years, I have developed Brick’s Law of Time Estimation. It works like this: when asked how long it will take to do x, think about it for as long as is practical, but don’t stress over the estimation. If you only have a few moments to come up with an answer, you can rely on your subconscious and just go with how long you intuitively think it will take. If you have time to put pen to paper, you might look at past experience, factor in the resources available, add a buffer for contingency, etc. In any event, by all means do your due diligence, but don’t stress over whether you considered everything or not. Let’s say you guessed that x will take you y (minutes / hours / days / whatever). Your final, best estimate will be as follows:

Time to do x = 2y

That’s it! Take your best guess and simply multiply that by 2. You’d be surprised how accurate this method can be.

Seriously, I have seen project management books that suggest calculating such an estimate as follows:

Time to do x = 3((t/r)^0.333)

where t is the overall level of effort in units of time per resource, and r is the number of resources. Wow – how does one even attempt to take a number to the power of one third in their head when they are just planning a trip to the store? My method is better because it is simpler. I win. Intuitively factor in the resources at hand into your best guess and multiply by 2. What could be easier?

Let’s run through an example: Your friend telephones, “how soon can you be over here?”. You start thinking to yourself “well, she’s about a 15 minute drive away, and I need 5 minutes to wash up before I leave, so I could be there in 20 minutes”. Wrong! Where’s the time to find your keys? Where’s the time to account for the traffic signal being down and having to wait through some unexpected traffic? Where’s the buffer for anything else Murphy throws at you? This is what you say: “I can be there in 40 minutes.” You put down the phone. You wash up, and you actually have your keys, but you can’t find your cell phone. You call your cell from the home phone to locate it by ring tone, and so what if it takes an extra 5 minutes. No traffic problems, but you realize you need some cash along the way – no problems, just stop at an ATM, you’ve got loads of time. You get to your friend’s place 34 minutes after you put down the phone. You are happy and relaxed. She admires your promptness, your respect for her time, and how you are one calm, cool and collected person. You achieve time management greatness.

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