blog

An assortment of thoughts.  Mostly tech related.

Brooks Law - Lines of Communication calculator - SIRI Shortcut

I’ve always loved the power of this visual from Lighthouse, representing Brooks Law and the number of lines of communication that exist in a team of a given size. It really demonstrates the mounting challenge of keeping people on track and in sync as team size grows:

 Image Source:  Lighthouse

Image Source: Lighthouse

Large team size presents significant overhead in terms of comms between the members of the team. The Scrum Guide has standardised on 6 +/- 3 as the best team size - so, between 3 and 9 people, PLUS the Scrum Master and Product Owner.

I can never remember the formula to calculate the number of relationships, despite it being quite simple - n*(n-1)/2 - so I put together this super-simple SIRI shortcut to help me out.

So…when you need to put the case forward for smaller team sizes this handy Siri shortcut can quickly prove a point. Simply enter the number of development team members and it spits out the number of lines of communication between the team members. Enjoy!

 Click  here  to download the Brooks Law/Lines of Communication ‘calculator’ shortcut to your iOS device…

Click here to download the Brooks Law/Lines of Communication ‘calculator’ shortcut to your iOS device…

Velocity and Capacity considerations for Sprint Planning

Velocity and Capacity are both critical metrics to consider in Sprint Planning.  As a reminder...

  • Velocity is a running average of the amount of user story points a team manages to achieve in its sprints - a historical view of what has happened

  • Capacity is a way of forecasting the team's availability (in the future) to work on stories in the upcoming sprint(s). Capacity is measured in time.

Capacity is affected by activities which can be represented as overhead - fixed and variable.

  • Fixed overhead represents the routine activities that the team members must be involved in sprint to sprint - such as Sprint Planning, Daily Standups, Backlog Refinement, Showcases/Sprint Reviews and Retrospectives and preparation for those activities. This can be considered as 'Scrum overhead'.  All of those activities take time and for a typical team using Scrum that adds up to around 20-25% of each team member's time each week

  • Variable overhead describes other occasions - this might be team offsites, town hall meetings, holidays, workshops and other non-Scrum/non-user story related work which affect the teams availability to get stuff done

So...consider this example:

Let's say a team has 4 team members that do the actual story work each sprint.  The team works to a 2 week sprint cadence which represents 10 working days. A working day (for sake of easier calculations) is 8 hours long.  Let's also assume too, that the team has an average velocity of 64 story points per 2-week sprint.

So, the team's capacity (incorporating Fixed overhead) can be determined as follows:


4 (team members) x 10 (days) x 6 (hours ie. 8 hours less 25% in fixed overhead) = 240 hours of time


This is the team's Normal capacity - which describes the maximum time the team has available to work on delivering User Stories.

Now, for an upcoming sprint you then deduct any Variable overhead that you're aware of.  Eg. Steve is going to be on leave for one day (6 hours), and the whole team has a half day workshop (4 hours x 4 team members = 16 hours) for a total of 22 hours of Variable overhead.

The team's adjusted capacity for the next sprint is 240 hours (normal capacity) - 22 hours (variable overhead) = 218 hours adjusted capacity.

Now, armed with this information you can calculate expected velocity for the upcoming sprint.  You do so with the following simple formula:


Adjusted Capacity/Normal Capacity * Average story point velocity = Expected story point velocity

e.g 218/240 * 64 = 58.13 points


During Sprint Planning you'd then look to bring into your sprint backlog about 58 points of work for the upcoming sprint.

Done.

Pecha Kucha - a Time-boxed presentation method (plus slide deck templates!)

Pecha Kucha is a lesser-known method of delivering concise, fast-paced presentations. Pecha Kucha in Japanese means 'chit-chat'.

The Pecha Kucha presentation style - similar to lightning talks - focuses on a few simple rules:

Pecha-Kucha.jpg
  • 20 slides

  • 20 seconds per slide (and slides are advanced automatically)

  • Slides are usually low on text, and are often just images to (hopefully, dramatically!) illustrate a powerful point to the audience.

Pecha Kucha (PK) Presentations are often done in groups. There are often multiple-speaker PK nights and meetups where people can come and learn a little bit about a lot of different topics. You can learn more about Pecha Kucha and watch a bunch of interesting presentations here.

I love the idea of these, and they borrow much from Agile/Lean thinking. I love the time-box constraints imposed, and the creativity they force as a consequence. Plus they eliminate waste!

Just 400 seconds (6 mins 40 seconds) to get your point across…

“Be sincere, Be brief, Be seated.”

― Franklin Delano Roosevelt

Downloadable Pecha Kucha Templates

While not especially difficult to create, I've created a bunch of blank templates for both Microsoft PowerPoint and Apple's Keynote. Each template has 20 blank slides with a 20 second automatic advance on each slide. I've included a deck for both 4:3 and 16:9 aspect ratios:

Download, drop in your images and practice! And, I'd love to hear/see some agile-themed PKs...