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The Lego Flow Game

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Joe Mcgrath, scrum master and coach in his latest blog explained the Lego Flow Game. The Lego Flow Game was created by Karl Scotland, lean agile consultant and director at Karl Scotland Ltd, and Sallyann Freudenberg, agile coach and IT consultant at Sallyann Freudenberg Consulting Ltd. They describe Lego Flow Game as:

The Lego Flow Game is a fun exercise and the aim of the game is to build Lego advent calendar items, with a defined workflow: finding the next advent calendar number (analysis), finding the matching set of lego pieces (supply), creating the lego item (build) and checking the item has been built correctly and robustly (accept). There are specialist roles for each stage in the workflow – analysis, suppliers, builders and acceptors – as well as an overall manager, and some market representatives. The game is run three times, each for a different type of process – batch and phase driven, time-boxed and flow-based.

Joe facilitates Lego Flow Game in his teams. He runs game in three rounds and compares the results as per CFD (cumulative flow diagram).

Round 1 – Waterfall

This is a single six-minute round. Teams should be given a pre-defined number of items that has been set as the expected target , and that this number of items (i.e. the whole batch) must be completed in each stage, before being passed in their entirety to the next stage. Thus the Analyst must find and process all 5 doors before all 5 completed index cards are passed to the Supplier, and so on. Stages are independent, with roles being specialist skills, so workers may not help each other. Any work which is sub-standard and rejected is stuck where it is – it is expected that all the right work is done to the right quality level first time.

Joe looked into the team's CFD. It is shown below:

Round 2 - Time-Boxed

This time, there are 3 sets of 2 minute time-boxes. Before each new time-box begins each team should estimate how many items they can complete within that time-box, and at the end they should review/retrospect how they did against their estimate. CFD of second round looked like below:

Round 3 - Flow-Based

This is another single six-minute round again. There is no need to estimate how many items can be done, but instead a WIP limit of one item per stage is introduced. This limit includes both items being worked on and those completed and ready for work in the next stage. Thus a basic pull system is created, such that only when a stage is empty may it pull a ready item from the preceding stage. CFD of third round looked like below:

He compared the results by looking at CFDs (cumulative flow diagrams). Third round was good in terms of delivering value early. Joe says that team was also able to deliver more in total.

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