Lean operations: process mapping, the eight wastes and continuous improvement

In most small businesses, slow operations have less to do with how fast people work than with what happens between tasks: work waiting in queues, being handed back and forth, or being done twice. Lean is a set of ideas, developed largely from the Toyota Production System, for seeing that waste and removing it a little at a time.

This guide covers the three tools most teams start with: mapping the process, spotting the eight wastes, and running small improvement cycles. It uses definitions from the Lean Enterprise Institute (LEI) and works through an office example, because lean applies to returns, invoicing and onboarding as much as to factories.

Start with what the customer values

The LEI’s introduction to lean puts it plainly: “Lean thinking always starts with the customer.” Value is whatever the customer would willingly pay for. Everything else is a candidate for removal.

The Japanese term for that everything else is muda. The LEI defines muda as “Any activity that consumes resources without creating value for the customer.” It then splits it into two types. Type one muda cannot be removed straight away, for example a quality check you still need because the step before it is unreliable. Type two muda can be removed quickly once you see it. The split matters because it stops teams tearing out controls they still depend on.

Map the process before you change it

You cannot remove waste you cannot see, and most processes look shorter in people’s heads than they are. A process map lists every step in order. A value stream map adds the information that makes waste visible: how long each step takes, how long work waits between steps, and who hands it to whom.

The LEI describes value stream mapping as diagramming every step in the material and information flows needed to deliver a product, and notes that Toyota developed it under the name “material and information flow diagram”. Teams draw two versions. The current state map records how work flows today. The future state map shows how it should flow.

To draw a current state map:

1. Choose one process with a clear start and end, such as “customer requests a return” to “refund received”.
2. Walk it. Follow a real case through every desk, inbox and system, rather than drawing it from memory in a meeting room.
3. Write each step on a sticky note in order, with who does it.
4. Under each step, record the working time (hands on the task) and the waiting time before the next step.
5. Add up both. Compare total working time with total elapsed time.

The gap between those two numbers is usually the first surprise. Work often spends far longer waiting than being worked on.

The eight wastes (TIMWOODS)

Taiichi Ohno, the Toyota engineer behind much of the production system, grouped waste into seven types. The LEI lists them as overproduction, waiting, conveyance, processing, inventory, motion and correction. Many practitioners add an eighth, unused skills. iSixSigma notes that this one was not part of Ohno’s original seven. The common memory aid is TIMWOODS:

The list is a prompt for looking, not a scoring system. When you walk a process, hold it next to each step and ask which of the eight you can see.

An example (illustration only)

A small online homeware shop receives about 30 return requests a week. Customers complain that refunds are slow. The owner and two staff walk the process with one real return and write down what happens.

Total working time is 23 minutes. Total elapsed time is about eight days. Holding TIMWOODS against the map, they spot waiting (the pile and the weekly batch), transport (the form going back and forth by email), defects (order numbers mistyped on the form) and overprocessing (the owner approving every refund, including small ones).

Their future state map uses a returns form on the website that pulls in the order details, a rule that staff inspect returns the day they arrive, and owner approval only above an agreed value. They do not change everything at once. They test the inspection rule first.

Kaizen and the PDCA cycle

Kaizen means continuous improvement. The LEI describes it as making “small, incremental improvements in processes and systems”, and quotes Ohno: “There can be no kaizen without a standard.” If everyone does a task differently, you cannot tell whether a change helped.

The engine of kaizen is the PDCA cycle. The LEI’s PDCA entry traces it to Walter Shewhart’s earlier cycle, which W. Edwards Deming developed for Japanese audiences in the 1950s.

1. Plan: set a target and the change you expect to reach it. “Inspecting on arrival will cut refund time by two days.”
2. Do: try the change, ideally on a small scale.
3. Check: compare the result with the target.
4. Act: if it worked, make it the new standard. If not, learn why and plan the next attempt.

Some people write it as PDSA, with “Study” in place of “Check”, to stress learning over inspection. Either way, the point is many small, tested changes instead of one large redesign.

Common mistakes

• Mapping from memory. The map shows the process as people believe it runs. Walk a real case.
• Measuring only working time. Most of the delay sits in the waiting, so record both.
• Treating lean as headcount cutting. Staff stop pointing out waste once improvement starts costing jobs.
• Removing type one muda too early. Drop a check only after the step it protects has become reliable.
• Improving without a standard. Write down the current way first, or you cannot tell whether the change made things better.
• Running one big kaizen event and stopping. The gains fade unless improvement becomes part of the weekly routine.

When lean fits and when it does not

Lean works best on repeated processes with a recognisable flow: order fulfilment, invoicing, onboarding, support tickets, monthly reporting. The repetition means a small improvement pays back many times.

It helps less with one-off creative or exploratory work, where the steps are not known in advance. There, the agile methods of short cycles and frequent feedback are a better fit. Lean also struggles in an unstable operation. The LEI warns that without a stable operation, teams “perform kaizen on top of chaos”. If volumes, staff or systems change every week, steady the process first, then improve it.