Lean development is not the same as Agile

Agile project management techniques recognise that software project management is mostly about communication between the ‘client’ and ‘development team’. Lean techniques instead focus on determining as quickly as possible what adds value and what does not. My experience is that lean techniques recognise that value is added most quickly by increasing ‘communication’ with the end user. This communication is rarely explicit. Lean techniques emphasise implicit communication through observed usage, metrics and comparative split tests – real data quickly trumps opinion. Lean accelerates learning, minimising work in progress and the cost of learning what really adds value.

Agile improves on Waterfall

Agile project management techniques recognise that software project management is mostly about communication. Older techniques such as the Waterfall process spent too much time attempting to capture and formalize what the client actually wanted. Often vast amounts of time and money would be spent writing and agreeing abstract specifications which invariably turned out not to accurately reflect what the client envisaged. The creation of these abstract specifications did not identify and predict the technical difficulties the project would face and the magnitude of problems. Many of you will have seen the Tree Swing Cartoon about requirements.

Agile techniques address these issues by emphasising communication between the development team and their client throughout the project; accepting that it is very hard to determine exactly what a client wants without delivering designs and working software. Clients will change their minds as they see how in reality the things they envisaged actually work. Developers will discover that some features they thought would be simple to implement are not so simple. Both party’s understanding of the facts on the ground improve vastly as they make progress. They both accept that they need a dialogue. Both parties accept that it is sensible to make changes to the project “plan” as it progresses to completion and delivery.

Agile addresses the communication gap between developer and client. The dialogue leads to sensible decisions, better use of resources (productivity) and greater predictability. Agile techniques means software development increasingly does a better job of meeting the expectations of its clients. However, often there is another very important person who’s been left out of the conversation, the end-user (e.g. the customer on an e-commerce site). Agile is still relying on the client’s ability to determine what the end-user wants and what works.

The development team can help with this process (that’s product development team, including product management, UX and developers). UX people often use usability testing techniques to gather opinion and identify problems with designs. These are really useful and valuable, identifying some problems, encouraging best practices and avoiding opinion deadlock. Unfortunately they are highly artificial, the few users in their tests are often not actual customers, with an actual need, using their own time and money.

If used correctly usability testing techniques can smooth the edges of a design, making it flow better and making it easier to use. However, they are based on small sample sizes, often gathered from the same geographical source and demographic. They often miss the nuances of other demographics and of how people actually behave when it’s their own money they’re spending. For example, I’ve seen data that showed 6% of UK customers attempting to use just their house number and postcode to specify their address, on many sites that is insufficient. What are the chances that this 6%’s actual behaviour would be picked up in a artificial usability test – unfortunately it is not high.

There is a new kid on the block which aims to address this gap and bring the 3rd and most important party in on the conversation – the end user, in HD and in all their magnificent glory, warts and all. The new kid is Lean Development.


In October (2011) Eric Ries’ best selling book, “The Lean Startup: How Constant Innovation Creates Radically Successful Businesses” (which I thoroughly recommend by the way) was released to critical acclaim and quickly became a New York Times Bestseller. Eric’s book focuses more on startups and product development rather than specifically software development per-say. The main theme it shares with Lean Software Development is this gap between what the experts in a business think about a product or service and the reality of what the end-user/customer values and how they use it.

The lean approach borrows its name from Lean Manufacturing techniques such as the Toyota Production System. Lean manufacturing works on the basis that parts are pulled through the manufacturing process as they are needed, work in progress is kept to a minimum. This makes the manufacturing process highly reactive to customer demand and able to cope with day to day manufacturing problems whilst maximising throughput. If orders for a product increase, more of its parts are pulled through the manufacturing system. If there is a problem with manufacturing of a part upstream, then it temporarily stops pulling the parts it depends upon up through the manufacturing process.

In software development we’re not talking about manufacturing but product development, the process of determining what features a product or service should have, how it should work and making the feature available. Our goal is to build things that users value, that help them achieve their goals. For example, in ecommerce that’s finding a site, finding the product they want and successfully purchasing the product.

Lean development recognises that experts are making calculated guesses about what problems a user has, what they will value and how they use a feature. There is nothing wrong with this. We need to start somewhere and an expert’s guess is a very good place to start and with no information to the contrary it’s also a good next move. However, it is a bet, we are betting that the expert is correct. Lean development aims to reduce our exposure to this bet by reducing work in progress to a bare minimum.

Using a lean process, each new release of the software contains the bare minimum additions/changes needed to test the experts assumptions. We determine what the user thinks through observing how they behave, collecting data through analytics and analysing our own databases and software logs. This Minimum Viable Product (MVP) or feature (MVF) is the least work we can do, the least money we can spend to test the expert’s hypothesis, to learn more and plan our next step.

This leanness, this minimization of work in progress is key. The emphasis is build something quickly, try it, look at data and feedback, improve – quickly, repeat. Lean is real and fact based, it implicitly involves the end-user, it makes them a key part of the product development conversation. The user drives the development process, implicitly prioritizing and “pulling” the new features or tweaks that they want through the development process.

Agile processes have plenty of regular conversation with the client, including regular demonstration of progress. When using an agile process, releases of new software with new features to the end-user are months apart. In a lean process, the conversation involves the end-user, so time between releases is measured in days not months.

In a Lean process, real data quickly trumps opinion as assumptions are quickly put to the test, features evolved – refined, modified or even removed. Ideas for what to try next are picked up from scents in the data. These scents are not always purely quantitive, for example an increase in the number of times a question is sent to the support email address may provide a clue to a problem or opportunity.

Lean projects ARE typically explicit goals where success can be quantified and measured, for example the number of sales per day increases. Agile projects often have explicit goals but ones that are not explicitly quantified, instead Agile projects tend to be specific about how much time is available. Lean projects tend to focus on achieving quantifiable value for the end-user. Lean development recognises that delivering real tangible business value is more likely if you iterate quickly and respond to what the end-user is actually doing.

Lean development is not agile development – lean extends the product development conversation to the end-user and minimises the businesses exposure to expert bets.

Of course, the real world isn’t quite a black as white as I’ve just painted it. In reality the differences between what Fred calls Agile and what Wilma calls Agile can be huge. Some people’s “agile” processes will look more like the Waterfall process whilst others will share the attributes of a lean process to a greater or lesser extent. So please forgive the blunt contrast I’ve painted to illustrate my points. I hope you’ve enjoyed this post.