Friday, May 20, 2016

Lean manufacturing vs Scrum - intro (part 1)

This is the first post in a blog series in which I intend to explore the relationship between lean manufacturing and software development, and how scrum can, or can not, help eliminate the seven wastes of lean.

We use scrum for software development at Xpedia. If you don't know what that is, check our methodology write-up on the subject or if your attention span is shorter try our slide deck.

Before starting, it is important to note that scrum has a strong aspect of continuous improvement, especially through retrospectives at the end of each sprint. While the retrospectives are an integral part of scrum, the improvement could be totally unrelated to scrum and more often have to do with the team's environment and specific challenges. These continuous improvements should therefore help eliminate waste of all flavours, so in an indirect way one could argue that scrum addresses all categories of waste. Similarly the important role of a scrum master can be argued to have a role to play in eliminating any sort of waste, but again this is rather indirect and probably depends heavily on how good the scrum master is.

For purposes of this series though, I'm going to ignore indirect benefit though these mechanisms and rather focus on the direct waste-elimination benefits of core scrum components as I see it.

You may also be familiar with the happily acronymed lean software development (LSD). There is a relation with scrum, but it's not quite the same thing. The terminology for LSD (yes, I have to call it that now), originated (according to Wikipedia at least) with a 2003 book, Lean Software Development: An Agile Toolkit, by Mary and Tom Poppendieck, who specifically took the principles of lean manufacturing and applied these to software development to come up with LSD. However, scrum predates this by several years and by 2003 was already fairly well established. Of course, the Poppendiecks knew scrum well when they wrote their book and it contains lots of nods to scrum, but it seems their background in various manufacturing environments led them to more directly apply the principles of lean manufacturing to software development in general and not just specifically through scrum. I'm going to probably lean rather heavily on the Poppendiecks' work throughout this series and will definitely also make use of various other sources, but will rather list these in the final post to make sure I include them all. I do recommend this book though, definitely a worthwhile investment of your time if this stuff interests you.

Before LSD, the overlap between scrum and lean manufacturing principles seems to be a bit more coincidental. Various authors did pick up on this, but to my knowledge the Poppendieck's seem to have been the first ones to actually take lean manufacturing principles and apply them directly to software development.

Let's get to the seven wastes now.

Lean manufacturing focuses primarily on eliminating waste and specifically identifies the following 7 types of waste:
  • Transport
  • Inventory
  • Motion
  • Waiting
  • Overproduction
  • Over processing
  • Defects
Others have attempted to add to this list over time, but mostly lean manufacturing focuses on these seven. Proponents of scrum may think this was stolen from scrum, but I assure you lean manufacturing is somewhat older than that! 

In the following posts I'm going to explore the extent to which there is an analogous waste in software development  and how this is minimised by following a good scrum process and also in what areas you'll need to think for yourself and cannot rely on scrum alone.

No comments:

Post a Comment