A Quick sketch of Lean
Tags: lean, safe, agile, development
Published: 2018-09-25 11:01:37

---
title: A Quick sketch of Lean
published: true
description: Some notes on Lean
tags: Lean, SAFe, Agile, Development
---

*One of the projects I work with has recently taken the decision to adopt Scaled Agile (SAFe) as a way of working. This has given me the chance to think again about some of the terms and concepts used and understand them a bit better.*

*This is the first in a set of quick sketches - please do comment as I'd like to know what I've missed or what would make this a more useful summary for others*

## Where does Lean come from? ##
Lean started as a set of principles Kiichiro Toyoda and Taiichi Ohno developed in the 1930s working at Toyota. Building cars on production lines was becoming more mechanized. At the same time, greater competition meant manufacturers had to be able to respond to the needs of customers with a wider range of options open to them. It wasn't enough to be able to build cheap cars by producing faster in bulk.  People wanted cars with specific features to meet their needs.

What emerged was the Toyota Production System. It was popular and effective. In other areas of industrial manufacturing, the ideas took root. In the 1990's,   James P. Womack and others <sup>[1](#myfootnote1)</sup> highlighted the principles to a wider audience. There was a sudden rush of Lean thinking.  Companies adopted the ideas to deliver a range of different products including software.

## Going with the 'flow' ##

What it changed was the emphasis. Lean in the name comes from the idea that a lot of the waste in any process is all the stuff lying around. Components waiting for processing. Components being moving from one place to another. Cars waiting for a customer to buy them. 

Lean suggests that companies could be more profitable if they can shed this weight.

Toyota re-organized their production line to minimize the time spent moving work between machines. They found ways to produce to improve the quality of the parts produced at each stage of the process. They reduced the number of parts produced, deciding the right number based on the rate that they could sell the completed cars.  Quick setups meant each machine could make small volumes of many different parts. Self-regulating machines and QA checks built into each process removed unproductive manual monitoring. These changes also reduced rework. Finding problems sooner meant fewer parts had to be replaced or repaired later in the process.

## What does Lean mean today ##


1. Understanding your products - what does the customer value?

    Lean expresses the world as production lines producing a product that is of value to a customer. This viewpoint is useful in that it encourages organizations to look at several questions:
    * What are the products produced?
    * Who are the customers who value these products?
    * Which products are the most valuable?

2. Mapping out the production line (value-stream)

    This perspective encourages organizations to consider what this production line looks like. SAFe describes it as a 'value stream'. A series of processes,  each process taking some work as input and transforming it. At the end of this line, a customer receives a finished product and returns some value is to the company. 

    Mapping out the process highlights where the structures and teams map well. It can also highlight activity or hand-offs that aren't so well aligned. This is helpful in as much as it helps teams or the organization to align with the most valuable work. It can also identify new customers or value streams.

3. Make the work in progress visible

    This means understanding where out the work is at any stage in time.  This means identifying each work item and representing where it is in a visual way. The most common representation of this is the Kanban board. The different variants on the team post-it board evolved from the ticket systems used on the early production lines to track stock levels.

4. Limit and track work-in-progress

    Getting the batch sizes right means limiting the number of tickets sitting at each stage. A sustainable level balances the quality, the needs of the customer and the available people and resources. Teams focus their attention at any places where there are a clumping up of tickets or tickets are taking a long time to flow through the system.

5. Fix bottlenecks, keep measuring and readjusting as necessary

    *Kaizen* means continuous (or even relentless) improvement. Focusing on one problem is likely to create a bottleneck somewhere else. It may also create a demand for more work from previous stages.  All improvement is an iterative process of readjusting. This readjusting has to include the whole of the production line or value stream to keep a steady flow of products to the customers that are paying for them.

## What is useful ##

* It gets away from focusing on individual projects or initiatives and conflicting priorities. The value to the customer of the end product defines the priority. Projects are part of the way the organization delivers that value to its customers.

* It introduces a model for understanding a pull-driven system. Producing as much as possible as fast as possible is often not the best use of people or resources. Operating at this sort of capacity has costs. These costs are not necessarily offset by getting more value back to the organization.

* It as an easy process to understand and adopt at any level from the individual to a massive organization:
    * Make the work visible. 
    * Remove the bottlenecks by aligning people and processes.  
    * Build quality into each stage.
    * Keep measuring reviewing and re-adjusting.

## Where it may need other perspectives to supplement it ##

* There may be a tension between 'continual readjustment' and the way teams naturally form and work.

    Part of the value that professionals bring to a job is their learned and embedded knowledge. Teams need time to learn to work well together. Individuals need a mix of challenges that expand their skills and the stability to apply the skills gained in a particular area.

* It gives a clear direction for *what* teams and individuals need to do to be successful but not *how* to do it.

    Other tools say more about how to build quality in and to maintain a sustainable flow.

----
<a name="myfootnote1"><sup>1</sup></a> See "The Machine That Changed the World" by James P. Womack and Daniel T. Jones for a biographical account of the changes introduced at Toyota. Womack and Jones followed this book up a couple of years later with a more implementation focused guide to the principles "Lean Thinking: Banish Waste And Create Wealth In Your Corporation".