Monthly Archives: May 2009

Planning Poker

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One of the things about writing software for a living is that customers are rarely happy when you tell them “It will be done when it’s done.” Even though development is fraught with uncertainty, it’s still incumbent upon us who practice this craft to be able to give people some idea of what kind of effort will be involved to implement a particular feature.

One way to do this is to have a project manager or senior programmer sit down, think really hard about it, and come up with numbers. This has the advantage of being  expedient, but the disadvantage of being almost certainly wrong. The reasons for this are many: it’s hard to estimate a job accurately when you’re not the person doing the work. All of us as individuals possess blind spots. And programmers are notoriously optimistic about how hard it will be to do something. (Not as optimistic as marketing people are when faced with a programming task, but still…)

One of the approaches I’ve seen that seems to promise the best results over time is Evidence-Based Scheduling. By having programmers estimate the tickets they’ll be working on, then record how much time they actually spend on it, comparing one to the other, factoring in how much productive time they have during the day once meetings, email, and the ilk are all done, and doing a lot of math, one can come up with good quality estimations — especially as one accumulates data on which programmers tend to exaggerate and which think they can finish nearly anything before lunch today. This approach has the advantage of producing really good estimates, but requires detailed tracking both of estimates and actual work time to produce good results.

Somewhere in the middle is Planning Poker, an approach that allows teams to collaboratively create estimates with a minimum of fuss. The basic idea is that you get all your developers together, give each of them a deck of cards with a time estimates written on each card, and have everyone choose how long they think a given task will take by throwing the corresponding card on the table. If there’s not agreement, everyone discusses it, explains their reasoning, and then you do it again until there’s a consensus. (You can read more details here if you’re interested.)

When we’re planning what to do for the next phase of a project, we have to consider two things: how important an issue is, and how much work it will be to do the fix. The latter has, up to now, been done off the cuff by whomever of the developers happened to be in the room. But in the past week, we’ve added a field to our ticketing system for estimates and started doing Planning Poker sessions to capture estimates for the tasks ahead. These seem to be going well, and I’ve noticed some interesting things about them:

  • These sessions are actually pretty fun. Nobody has come away hating the process, and several of the devs involved have said they’ve really enjoyed them.
  • Because the rules of the game call for the people with the highest and lowest guesses to explain their reasoning, we hear from people who are sometimes a bit more reluctant to speak. Having their opinions respectfully listened to can be a very affirming, especially for new folks who may not have a history with the team yet.
  • We’ve actually been doing on-the-fly technical design as we discuss the issues, and have come up with some really good ideas and insights that we’ve then recorded in the ticket since we already had it open there. This was a pleasant surprise to me; I’d only been hoping to get estimates, but have also benefited from some terrific collaborative technical brainstorming.
  • It provides natural cross-training, since even programmers who aren’t involved in a particular project get to listen, ask questions, and vote on its tickets.

So after two sessions, I’m counting Planning Poker as a success, and have scheduled regular sessions to finish estimating our backlog of tickets and to handle new ones as they show up.  Many thanks to Mike Cohn for the great writeup that got me excited about it!

Facebook and the Coming Zombie Apocalypse

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My good friend Daniel Priest recently posted the following to his Facebook profile:

Daniel Priest is a tree climbing fool

I thought that it was important that the conversation that ensued be available for posterity outside of Facebook’s domain, so here it is. When the undead rise up, you’ll thank me.

Matthew Christopher Davidson, May 8

Fanny, apparently you’ve married a monkey. I bet he looks cute in a ten-gallon hat.

Jonathan Hunter, May 9

Trees are pretty.

Sean McMains, May 10

It’s good to know that when the zombie uprising comes and I need someone to hoist me into the upper branches of a magnificent magnolia to escape the zombies’ brain lust, you’ll be around.

Matthew Christopher Davidson, May 10

Wow, I just learned that zombies can’t climb trees.

Sean McMains, May 10

Have you ever seen a zombie perched in a tree? Well, there you go.

Jonathan Hunter, May 10

Matthew, Sean may have learned this from Shaun of the Dead. One of the characters, Diane, is able to escape the zombies by hanging out in a tree until she is rescued by the British Army.

Sean McMains, May 10

(Of course, I’m discounting the rare South American Arboreal Zombie here…)

Daniel Priest, May 10

The zombie lore on display here is sadly lacking. Zombies may not climb trees, but they do climb other zombies. And when the moaning, staggering pile of mindless undead under the tree reaches high enough…

Matthew Christopher Davidson, May 10

The only thing I have ever heard of zombies being able to ‘climb’ is stairs. You would have to have a zombie staircase. That would pretty much never happen, since zombies are not capable of cooperating intelligently.

Matthew Christopher Davidson, May 10

Zombies might be able to pull themselves out of their graves by using the bodies of other zombies if they were buried in mass graves, but to accept the possibility of anything beyond that I would have to see an example.

Jonathan Hunter, May 10

I think Matthew is onto something here. In order to make plans and such, one has to be conscious. But zombies aren’t conscious, so they can’t make plans. It’s logic.

The only way, then, that a zombie could get someone from a tree would be if it just so happened that a bunch of bodies and other artifacts were piled up in a a certain way and that zombie just so happened to make its way up that pile. But, as Matthew said, that would pretty much never happen.

Sean McMains, May 10

Jonathan: I call shenanigans on your logic here. How can you possible assert that zombies aren’t conscious? Certainly it takes consciousness to shamble and to cry “brains! BRAAAAIIIINS!”

I think you’re just a closed-minded lifeist.

Daniel Priest, May 10

Big sigh.

Let me spell it out here, since the bunch of you have evidently watched a total of about 25 minutes worth of zombie movie material. Zombies smell living human flesh up in the tree. The first zombies start moaning and clawing at the tree. Additional zombies are drawn by the moaning of the first zombies. As the mob grows, zombies at the middle of the pile are trampled, piled upon, etc. Over the course of the night this zombie mound gets higher and higher.

Y’all are the meat snacks in the film who climb the tree at the beginning of the night, look down at the zombies, and say something like “Alright, I think we’ll be safe here,” before being awakened in the middle of the night by a cold hand gripping your ankle, dragging you down to immediate dismemberment.

It’s when you think you’re safe that you’re in the most danger. When you think you’re in danger, well, you’re in danger then too. You’re never safe. Remember that.

Matthew Christopher Davidson, May 10

Daniel,

It’s not the herd instinct that I question. It’s the sheer physics. I don’t believe everything I see in movies. Movies are unreal scenarios as we all know well.

Any movie maker who scripted the scene you’re describing would have to be ignorant of the problem. As soon as your hypothetical mound reaches the height of a human being, unless it is the width of a football field with a gradual grade, zombies have to climb. Zombies don’t climb. They walk.

By the time enough zombies have pooled to create a nice pleasant hillside stroll to the top of my tree, the US Marines have arrived and helicoptered me out of the joint because it has been three days.

Matthew Christopher Davidson, May 10

I never said zombies weren’t conscious, for the record. I don’t care if they’re conscious. They’re not capable of cooperating intelligently.

Ross Richie, May 10

SIGH.

Okay, everyone take notes. THIS IS HOW IT REALLY WORKS (points to Priest for trying):

ROMERO ZOMBIES: are mindless. Priest’s example is true there.

RUSSO ZOMBIES: are smart, capable of thought, can wield tools, etc., and can talk to you, crying out for brains. Those zombies will climb that tree, no problem, and this is NSFW: http://www.youtube.com/watch?v=EPc7c4W6btY&feature=related

Or, as you can see in this clip, they have the ability to try to talk to you and smash through the trap door in the attic: http://www.youtube.com/watch?v=LD8_GFEO-HY&feature=related

For those taking notes at home: Russo and Romero collaborated and created the genre in NIGHT OF THE LIVING DEAD, got into a Lennon and McCartney-esque squabble, split up, and individually created competing zombie franchises, hence creating seemingly conflicting rules to how the zombie mythology works.

Ross Richie, May 10

Amateurs. I love you guys.

Jonathan Hunter, May 10

I was going to let Daniel have the last word, but I can’t let this go.

Romero zombies wouldn’t be able to climb trees, as Matthew has demonstrated. And if we’re talking about Russo zombies, then you wouldn’t be silly enough to climb a tree. So, it doesn’t matter what kind of zombie we’re dealing with. They wouldn’t be able to pluck you out of a tree.

Ross Richie, May 10

HOOO-KAY. Didn’t wanna play this card, but looks like I’ll have to.

Everyone that’s published (i.e. poured 10s of thousands of dollars into) a series called ZOMBIE TALES that is a signature part of your corporate identity, raise your hands.

Now that we’ve gotten that outta the way… (HARSH!)

Romero zombies will get you in exactly the way Daniel laid out. They’re a swarm monster, and the swarm will pile up and attain height….

RE: climbing a tree in a Russo flick, if you’re willing to hide in an attic, you’ll hide in a tree. And they’ll climb it, while crowing about the need to snack on your brains.

LOVE YOU JONATHAN, MEAN IT!!!

Jonathan Hunter, May 10

I feel like I’m in crazy town and Ross is the mayor.

Everyone that had a normal childhood (i.e. played outside with other children instead of rotting away in front of the television box while eating pork rinds) that is a signature part of your personal identity, raise your hands.

Romero zombies COULD get you in that way, but they don’t swarm fast enough. The Marines would rescue you first.

I wouldn’t hide in the attic, so I also wouldn’t hide in a tree.

Matthew Christopher Davidson, May 11

Pouring 10s of thousands of dollars into zombie literature doesn’t automatically make you right. In fact, it might make you stupid. Oh snap.

I am grateful for this broadening lesson, however.

I know very little about zombies, but I do not accept statements merely on the basis of varying and respectively unquestionable zombie traditions. I am trying to learn by questioning everything and using careful reasoning. In this way I hope to one day truly be a philosopher.

Daniel Priest, May 11

Ross–thanks for the input. What did you think of World War Z?

Jonathan–I think you’re right. You aren’t the sort to hide in an attic or tree. I think you might be the zombie imitation sort, try to make your way into the countryside by walking, moaning, etc. like a zombie, thereby escaping notice. Good luck with that.

Matthew–Physics of zombie accumulation. We assume a maximum slope of 45 degrees and a cone height of 40 feet. Sean specified the upper branches of a magnificent magnolia. In the thin alkaline soils of central Texas <i>Magnolia grandiflora</i> will attain a height of no more than 50 feet, so if we’re in the very upper branches the zombies would need to be approximately 40 feet high to be in ankle grabbing distance. This is an absurdly generous estimate of both tree height and sturdiness of upper branches, btw. But I’m a generous guy.

The zombie cone will have a volume of approximately 67000 cubic feet. Assuming an average zombie volume of 10 cubic feet, you’ll need 6700 zombies to arrive during the night. If zombies shamble at 4 miles an hour every zombie within 32 miles could conceivably arrive within the course of the night. And there’s a hell of a lot more recently dead and/or soon to be bitten and infected people within 32 miles of San Marcos, Texas.

If only 3 zombies spot us initially, and each of them with their moaning alerts only 3 additional zombies, each of whom alert 3 more, etc, and each of them does so within 30 minutes (again, very generous–in an urban setting far more zombies are likely to hear, and much more quickly), then we could conceivably have 20,000 zombies at the tree within 5 hours.

Not that they’re all going to come for us–there are presumably other equally tasty people in other trees–but I think the plausibility of the scenario has now been pretty well established.

Jonathan Hunter, May 11

Daniel, I thought you would know me better than that. I’m not the imitating type. I’m the joining type. I wouldn’t hide in a tree or attic because I would rather become a zombie and come after all of you myself. I’ll admit that I don’t understand how the conversion process works, but that would be optimal.

Ross Richie, May 11

MCMAINS!!!! MCMAINS!!!! THIS IS ALL YOUR FAULT, MCMAINS!!!!

Sean McMains, May 11

Ross,

If my studies in Zombie Lit. have taught me anything, it’s that the person who sets himself up as a pompous authority figure will be among the first to be devoured by the ravenous hordes.

Thus, by erecting yourself as an authority figure — a verb I here find particularly apt, given your apparent desire to turn this into an exercise in comparative phallic metrics — you have thrust yourself — verb, ditto — into the head — noun, ditto — of the line of victims.

Sean

P.S. New personal best for oblique naughty jokes in one sentence! YES!

Sean McMains, May 11

Daniel,

While I’m loathe to give offense to the very person on whom I will be relying to save me from the apocalypse, I do find a few of your premises troubling:

1. A 45° slope seems singularly optimistic, especially with modern, low-friction synthetic clothing. Perhaps this would be reasonable if the zombies weren’t wearing much (not unreasonable in San Marcos), or were wearing clothing with natural fibers that would have a higher coefficient of friction. I would hold that a figure closer to 30° is likely. That would give us a radius for the cone of 69′, and therefore a volume of 199,427 cubic feet.

2. 10 cubic feet is an absurdly large figure. Consider that human bodies are approximately as dense as fresh water, as shown by the fact that many of us can sink or float in a pool depending on how deeply we breathe in. Water weighs 62.4 pounds/cubic foot. American men average around 180 pounds, women around 140. Thus, a 160 pound “average person” would have a volume of around 2.56 cubic feet. (Alternately, think about how many foot-square boxes Steve Buscemi would fill at the end of Fargo.)

Thus, with the new figures, we’d need 77,901 zombies to build a sufficient pile.

3. Your zombie-alert figures presuppose that zombies’ communication is at least sophisticated enough to convey bearing and distance over miles. I’m not sure how much nuance one can pack into the word “Braaaaiins…”, but my tentative experiments this morning with my coworkers aren’t promising.

Alternatively, perhaps zombies work like ants do, and leave a pheromone trail to food sources. This bears further investigation.

Ross Richie, May 11

McMains — the new popular variant in horror is that they can SMELL the living.

Doesn’t make a whole lotta sense to me, but characters in THE WALKING DEAD smear themselves with zombie smell and sneak past the zoms undetected. The horror community’s glommed onto that and adopted it.

Of course, all this goes out the window if you are loyal to Romero, who established the zoms are getting smarter in LAND OF THE DEAD, where they begin to use tools. LAND OF THE DEAD zoms would be able to scale that tree, no problem. Hell, they’d prolly grab some power tools and just cut it down…

In the trailer here, you’ll see they reference “they’re thinking, they’re communicating” and there’s a brief clip of them using a machine gun, so maybe it’s all moot, they’d just SHOOTCHA OUTTA THE TREE!

http://www.youtube.com/watch?v=atXJB9luiko