Shopping in our local Grocery Store (Farm Boy) on a recent Saturday made me realize what a good job they do Limiting Work in Progress (WIP) and Self Organizing. Driving into the parking lot with my 4yr old, I was dreading the busyness of the store. When I got in, the place was packed, and trying to manoeuvre even a small cart with a 4yr old driving was quite the experience. I had expected the checkout experience to be easily 10 minutes long, an eternity even with the best behaved child.
When I entered the store there were only a few people on cash and the lines seemed to be building. By the time we were ready to checkout half an hour later, all 9 cashes were open and we waited less than two minutes.
What happened? A couple of conversations with cashiers have helped me piece together the key points:
- They all recognize that Farm Boy doesn’t make money until you’ve paid – a Customer with unpaid groceries is Work In Progress. After all if you only have a few items and see a 10 minute line up you might just leave. Especially if the 1-8 items queue is also deep.
- If there is a line up, cashiers just start opening lanes until the bottle neck is cleared
- Many of the staff can work the cash, so you’re rarely stuck waiting for another cashier
- Staff don’t wait to be told to open cashes they just do it
- When demand ebbs, the cashiers start to close and return to other work
So effectively they’ve seemed to discovered the Theory of Constraints (TOC) and they Self-Organize to eliminate the bottleneck. Their system is informal, but even without sophisticated measurements you can still observe and eliminate bottlenecks. Compare this to another large Canadian grocery chain where I often line up for 10+ minutes, just waiting to get to the front of the line. Guess which store gets more of my business?
In the software world, QA, especially when all the tests are run manually, is often the constraint we find. So we need to take steps to eliminate the bottleneck:
- Automate your Regression Tests, so that you have a minimal (if any) manual regression work to do
- Train everyone on the team in the basic of QA
- When work builds up in QA, cease writing new code until the existing code has been tested and the tests automated
- Start write your application using Acceptance Test Driven Development
Eventually QA stops being the bottleneck, at which point we re-examine the system to see if the bottleneck has moved again. When that happens, take similar steps all over again to eliminate the next bottleneck.
What bottlenecks have you observed in your grocery store? Your development process?
Another Theory of Constraints post: “Theory of Constraints in Software Development”
Mark Levison has been helping Scrum teams and organizations with Agile, Scrum and Kanban style approaches since 2001. From certified scrum master training to custom Agile courses, he has helped well over 8,000 individuals, earning him respect and top rated reviews as one of the pioneers within the industry, as well as a raft of certifications from the ScrumAlliance. Mark has been a speaker at various Agile Conferences for more than 20 years, and is a published Scrum author with eBooks as well as articles on InfoQ.com, ScrumAlliance.org an AgileAlliance.org.
Gil Broza says
Loved this post, Mark. We shop at several different grocery stores and for the most part, they don’t get it. In particular, the phrase “the store doesn’t make money until you’ve paid”.
As a customer, I can definitely pick up on the energy of the employees and their motivation to perform non-cashier roles, or to initiate the opening of a cash register. The more centralized the action, the less they actually open, and the less I feel valued as a customer.
The one exception to your post seems to be Wal-Mart. The lines there are few and always infernally long — and business is booming. I guess they can get away with anything at the prices they charge.
Great post – I love this metaphor! It’s impressive that the employees are comfortable taking the initiative to hop on and start ringing up customers without being told. I imagine training your team to work that smoothly would be the biggest challenge.
Mark Levison says
Michelle – thanks for taking the time to comment. While the training is difficult I gather management has made it clear “help the customer purchase groceries is the only priority”. A clear goal is necessary to making self organization work.
I’ve also discovered several of the staff have moved to this store from a large Canadian grocery chain because of the customer focus.
I’ve read that the fathers of Lean at Toyota were much inspired by US supermarkets. Maybe more by the supermarkets than by the Ford factories they came here to visit.
Kirk Bryde says
The fathers of Lean were impressed by how the USA supermarket shelves were filled throughout the day, by using the shelf space as a sort of Kanban token within a “pull system”. So instead of a fancy inventory control system tapped into the POS system, the shelf stockers just looked for empty shelf space, and figured out JIT that those items were selling fast (i.e. pulled by customers) – so needed restocking. One of the first “pull systems” – brilliant in its simplicity!
Mark Levison says
Kirk – I’m with you simple human driven systems work best, they’re adaptable and can improve as they learn.
Great post, Kirk! I’ve been implementing lean approaches in my work and personal life for a few years now, and grocery stores often come up in my conversations and thoughts about creating smooth flow and limiting work in progress. A couple of our local chains have, for example, cottoned on to the fact that having a single feeder line served by multiple cashiers is the most optimal solution, rather than having a dedicated line per cashier. With the single feeder line, customers with fewer items are not held up by that one single client with the mountain load of shopping or third party bills to pay. The overall throughput is higher than when people hop from line to line, thinking to fast-track their payment – and then getting stuck behind somebody anyway.
Personally, I’ve started loving another built-in mechanism that limits WIP: the size of trolleys and baskets. Most chains here provide at least three sizes, sometimes more, ranging from a hand-held basket to large trolleys. Before I started living my life (and our family’s!) on the principles of lean, I would often drag an overloaded basket to the cashier, usually causing me to have to put the bill on my debit card and buy additional shopping bags. Now, I take the container/token size to heart when I choose one, and that immediately sets the scope of the shopping trip for me.
Of course, I’m sure the supermarket wants me to upsize as I go along … 😉
Mark Levison says
Maritza – brilliant I had never considered the implicit limits of basket/trolley before. In fact when I grab a basket I usually overfill it (think milk and eggs) 🙂
Sorry – I meant Mark, of course! 🙂
Bruce Onder says
I noticed at Walgreens they have a code “IC3” which they announce when there are more than three people at the main register. However, it’s not as good as the system described above because I think it came from the managers and not the team.
Mark Levison says
While there is a difference in empowering the workers and there increasing their engagement, from the consumers point of view it just makes the place work better.