private thoughts about life behind data processing

Monthly Archives: joulukuu 2015

Completely Fair Scheduler

It’s heard often that concentrating to one thing is good. Many agile methods assumes that there’s only one project going on. Also principles of Lean Development¹ implicates a glory of single project by encouraging to keep cycle time low. Deliver as fast as possible.

One project at a time is good. Among many benefits, it helps to

  • confuseddeliver fast;
  • keep queues short;
  • keep focused;
  • prevent multitasking.

But there’s an other side. According to Bernice Eiduson extensive studies², most successful scientists tend to have many fields of interests and they change their focus between them oftenIt’s natural, connecting things is vital to creativity. (Actually, I believe that real creativity happens when solutions conflict creating a new reality.)

I don’t see why having multiple projects going on would be good specially for scientists. Being able to see different aspects and having vast variety of skills is good for anyone doing creative job like software development. And as Mr. Appelo puts it³, having multiple projects:

  • keeps your days versatile;
  • prevents you to bang your head in a single problem all day long;
  • provides flexibility, as normally always some project is waiting for something.

It’s good to remember though that multitasking is still bad. It destroys brains and decrease performance.But switching tasks couple of times a day is not the same than checking emails every minute. Actually, distractions may be the best things happening to you5. Distraction ”may provide the break you need to disengage from a fixation on the ineffective solution5”.  And even without distractions switching tasks every now and then may help your creativity. According to Shelley Carson’s and Justin Moore’s studies task switching slowed problem solving but increased divergent thinking6.

connecting_bossSo how many projects one should have? Of course it’s a personal thing… …but some analysis can be done. First, feedback loop need to be fast enough so that things stays in mind and one can react to the feedback got from customers or other sources. Second, although it’s not good to stuck for too long in on problem, harder the problem is more time you need for it. Complex problems can’t be solved in seconds.

Mr. Donald G. Reinertsen speaks in his book ’The Principles of Product Development Flow: Second Generation Lean Product Development’7 about Marines who put all their power to the most focal point. In case one’s not Marine or establishing a startup, it’s impossible to have only one focal point. But there should not be more projects going on than there’s ”best value projects” available; it’s always better to put more effort to fewer valuable projects than having theatrical projects for showing much activity. And final reminder: two many projects causes multitasking.

Let’s take a real life example: In my job we do product development based on account managers’ orders. We have more account managers than we have software developers. For one software developer we have two contact managers, each making orders. Most of the orders are quite small. We use in average about 5 days to complete the order. Still, we have always couple of long infrastructure projects going on. We are a DevOp team; we have our own infrastructure development and up-keeping activities going on all the time.

So, at a time, for every developer there’s two account managers waiting for order to complete and at least one task to maintain the system. In theory we have three projects going on with every software developer. How would that make developer’s day look like (hope she’s understood that multitasking is bad and is doing things in junks):

  • 2 hours for ”doing nothing in particular”
  • 1 hour for mail, keeping things in order and bureaucracy
  • 1 hour for project 1
  • 1 hour for project 2
  • 1 hour for project 3
  • 1 hour hour for preparing next project and learning

Pretty fair.







Personal Mission

It’s always good that companies have a mission. Sometimes it’s even stated to be a requirement to survive. But not all work places have that clear mission or it’s not always easy to derive a purpose for one’s every day life from companies’ high-flying nonesense.

That’s why it’s good to make clear you personal mission statementIt can be something very personal and very narrow. But it can’t be in conflict with your employer’s mission.

After this, when getting contradictory signals, it’s easier to decide what’s good for own goals.

My employer’s statement goes: The Finnish Meteorological Institute mission is to produce high-quality services and scientific know-how on the atmosphere and seas. The Institute uses its expertise to provide services that promote public safety and enhance well-being among people and in the environment, taking into account the needs to maintain preparedness.

From that I have derived a statement for my group: Customer Solutions makes the best weather services in the World. We are fast and agile group with a state of the art knowledge of the newest technology and special skills to handle large data volumes. 

For me the statement stands:
I develop my environment giving my group proper goals to achieve and best possible premise to meet them. I learn more about management, architecture and spatial services.

But often I summary it:
I learn and develop.


I’m an enthusiastic software professional with a strong vision of high quality software and usability. I design systems in a modular service oriented way still keeping balance with performance and simplicity.

My special interests are in team management, architecture and spatial services. I see myself as a gardener who creates prober goals, boundaries and feedback for team to be productive and develop itself.

I want to learn and develop and I always give a 100 percent of myself to what I am currently doing.