Lean: what it is and how to apply it

Lean is a way of working that puts the flow of work through a process centre stage and strips out everything the customer isn't waiting for and won't pay for. The goal is a shorter lead time with less waste — not working harder, just less standing still. Lean applies to any process that repeats, from manufacturing to invoicing to lead follow-up.

Want the bigger picture first? Read Lean Six Sigma. If your issue is more about scatter and errors than slowness, see Six Sigma.

Where Lean comes from

Lean is the Western name for the thinking behind the Toyota Production System, built on two pillars: producing just-in-time and stopping immediately at a deviation, so a problem gets solved rather than passed along. Toyota describes the system itself. The term "lean" and its translation to non-manufacturing settings come from the work of Womack and Jones, who set out five principles.

The five principles of Lean

1. Value — define value from the customer's point of view, not the department's.
2. Value stream — map every step from request to delivery, including waiting time.
3. Flow — let the work move: fewer batches, fewer handoffs, less standing still.
4. Pull — start work only when there's demand, instead of building up stock.
5. Perfection — keep improving in small steps, together with the people doing the work.

The eight wastes (TIMWOODS)

Of the eight, waiting is almost always the biggest one in office and service processes. That's why cutting approvals and handoffs usually pays off more than speeding up individual steps.

• Transport — work that bounces back and forth between departments.
• Inventory — half-finished drafts, waiting tickets, unhandled leads.
• Motion — searching five systems for one piece of information.
• Waiting — waiting on approval, feedback or delivery.
• Overproduction — reports and features nobody uses.
• Overprocessing — double checks, too many review rounds.
• Defects — rework, corrections, complaints.
• Skills (unused talent) — specialists doing routine work.

The tools you'll actually use

Value stream mapping is the starting point; the Lean Enterprise Institute describes the standard format. Build the map together with the people doing the work, on paper, in one session.

How to run a first Lean round

1. Pick one process that occurs often and that people find frustrating.
2. Write down the steps as they actually happen, not as they're supposed to happen.
3. Time one job's net processing time and its total lead time.
4. Mark every step as value, control or waiting.
5. Cut or combine anything nobody can explain; start with waiting.
6. Document the new way of working and track the same number for four weeks.

A first round usually takes one session of two to three hours plus a week of measuring. In administrative processes, we more often see lead time halve than processing time — because the gain sits in the waiting.

Pitfalls

• Cutting a step without knowing what it's for. Some checks exist for a reason; always ask about the incident behind them.
• Using Lean as a cost-cutting programme. The moment it becomes about removing people instead of removing work, the flow of improvement ideas stops immediately.
• Only looking at your own department. The biggest waste usually sits at the handoffs between departments.
• Not writing down a standard. Without an agreement, the process slides back within weeks.

Lean or Six Sigma?

Choose Lean when you can see where things get stuck and the problem is slowness. Choose Six Sigma when the outcome fluctuates and nobody knows why. Facing both? Follow DMAIC with a Lean round upfront — the approach is laid out in Lean Six Sigma.

Sources

• Toyota — Toyota Production System
• ASQ — Lean
• Lean Enterprise Institute — Value stream mapping