Waiting Waste: When Machines, People and Orders Stand Still

What is waiting waste?

Waiting waste is time when people, machines or parts stand still because the next thing is not ready. When an operator waits, we pay wages for no work. When a machine waits, its capacity is lost. When an order waits, delivery slips and money stays stuck.

Most owners look at how many hours the machine ran. Few look at how many hours it stood while the operator was present. That gap is waiting.

Who is waiting in your plant?

Waiting has three faces.

• Machine waiting. The grinder is ready but the crane has not come.
• People waiting. An operator stands by for a first-piece approval.
• Parts waiting. Half-finished parts sit in crates between two machines.

In the shop

• A job waits for a drawing, the CNC code or material from the store.
• A machine waits for the quality person to approve the first piece.
• An operator waits for a tool insert that is out of stock.

In the office

• A purchase order waits three days for a signature.
• A truck waits at the gate for the invoice.
• A decision waits because only the owner can take it.

What does it cost? An example

A grinding bay shares one overhead crane with the assembly bay. Each grinding job needs the crane to load and unload. On average the grinder waits 20 minutes per job, and there are 4 jobs in a shift.

• Waiting per shift: 4 × 20 = 80 minutes.
• Shift time: 450 minutes.
• Share lost: 80 ÷ 450 = about 18%.

(These numbers are an example.) Nearly a fifth of the machine's day is gone, every day, and no one sees it on the production sheet because the operator was "at the machine".

A small hoist fitted at the grinder cut the wait for handling to a few minutes. The fix did not need a new machine. It needed someone to look.

Why does the slowest step matter?

Take three machines in a row. The first makes a part in 4 minutes, the second in 6, and the third in 10. The third machine is the slowest. Parts pile up in front of it. The two machines before it can run faster, but that only builds a bigger pile.

The whole line makes one part every 10 minutes, or 6 an hour. It does not matter that the first machine could make 15 an hour.

The slowest step sets the pace for everyone. The waiting is always in front of it.

So the first question is not "How do we make machine one faster?" It is "What is making the slow step slow, and how do we keep it from ever waiting?"

Why does waiting happen?

• Shared resources. One crane, one forklift or one inspector for many machines.
• No preparation. Material, tools, drawing and CNC code are not ready before the job starts.
• Decisions held by one person. Everything waits for the owner or one head of department.
• Uneven work. One step is overloaded while the next one has nothing to do.
• Breakdowns and long setups.

How do we reduce waiting?

1. Kit the job. Bring the material, tools, inserts, drawing and CNC code to the machine before the job starts.
2. Fix response times. For example, agree that first-piece approval is given within 10 minutes. Then track it.
3. Delegate decisions. Write down who can decide what, so work does not queue for one person.
4. Support the slow machine. Give it a hoist, a tool trolley and an inspection point close by.
5. Record waiting by reason. Note the stop, the reason and the minutes. What is measured can be reduced.
6. Balance the line. Where possible, move work from the slow step to a faster one.

How to start in your plant

1. Choose one machine that matters most to your delivery.
2. For one week, note each time it stops and the reason, in minutes.
3. Add up the reasons. The top one is your first project.
4. Fix it, then repeat.

Many owners are surprised. The top reason is often not breakdown. It is waiting for people, material or a signature.

Play the video: Waiting Is a Waste: The Silent Productivity Killer