The windscreen wiper: a complete value study

The brief: take at least ten per cent, four pounds fifty-three, off the system's cost, with every legal requirement and design target still met. Two hundred and fifty thousand cars a year, for five years.

Where does the money sit? The motor and the linkage, which only get motion to the arms, are nearly half the cost. The blades, which do the wiping, are six per cent.

Rank the parts by cost. Twenty-two of the forty-five make up eighty per cent. That's flatter than the usual twenty-eighty, because a wiper has no single big part. And the top two are both washer pumps.

Next, the law and the tests. The wipers must clear ninety-eight per cent of the area in front of the driver, at two speeds. They must survive being held still for fifteen seconds at full speed, and keep working at minus eighteen degrees.

Then the field. Public recall records show the same two causes again and again: water getting into motors and ball joints, and electronics inside the motor. Any idea that touches these needs the hardest tests.

And the driver. Wiping the legal area, and a washer that works, are must-bes. Quiet, long-lasting blades are more-is-better. And a low-fluid warning light? Most drivers in a mild climate never notice it.

Finally, what moves the forty-five pounds twenty-eight. The price of the pumps matters most: a pound more on each adds two pounds sixty a car. Another clue pointing at the washer.

With the brief signed and the facts checked, the team can start on functions.

The creative phase takes each target function in turn and asks one question: how else could this job be done? Not 'how do we make this pump cheaper', but 'how else could the rear screen get fluid?'

Combine, from the SCAMPER checklist, gives the biggest idea: one reversing pump that feeds the front jets one way and the rear the other. One pump, one grommet and one wiring branch go.

Benchmarking other cars gives fan jets. Their maker says they use much less fluid for the same clean, so a two-litre bottle lasts as long as today's three. That's a litre less to carry, too.

The Kano work gives another: fit the low-fluid sensor only to cars with the winter pack.

Function by function, a technology scan, benchmarking, SCAMPER, and the recall records. Twenty-one ideas, and nobody judges any of them yet.

Now a trap. A supplier suggests using ferrite magnets instead of rare-earth ones. It sounds like a saving, but this motor already uses ferrite. A saving only exists against the design you actually have. Check the baseline before you count it.

Six ideas were screened out, each with a written reason. They're kept, because next time the reason may have changed.

Fifteen ideas came through screening. Now the team has to choose, and do it fairly.

First, a quick picture. Saving a year against the one-off cost. The reversing pump lands top left: nearly a million pounds a year for forty-five thousand. The reversing motor lands bottom right: a million eight for forty-five thousand a year.

Then the weighted matrix. Five criteria, with weights the team agreed before scoring anything: saving, risk, what the driver gets, one-off cost and speed.

Each idea is scored one to five on each, then weighted. The platform motor and the washer ideas come out on top.

Composite arms and plastic pivot housings save well but carry real risk, so they go ahead only after a feasibility check.

Watch what happens if someone pushes the weight on saving up to a half. Two decisions change. That's why the weights are agreed first. Otherwise anyone can tune them to get the answer they want.

The reversing motor comes last. It saves eighteen pence a car on cost alone. But it's lighter, parks the arms lower and makes rain detection easy. Scoring on cost says hold. The next film asks whether its value changes that.

The team builds two business cases: one that pays back in weeks, and one that only makes sense when you count more than the piece price.

The washer package: one reversing pump, fan jets with a two-litre bottle, the sensor in the winter pack, and a second pump supplier. Five pounds fifty-one a car, one point three eight million pounds a year, for a hundred and thirty-five thousand pounds one-off. It pays back in about five weeks, and on its own it beats the ten per cent goal.

It also takes more than a kilogram off the car. Carmakers pay fines for every gram of CO₂ over their target, so weight has a value. The team uses a cautious four pounds a kilogram, which pays the package back in under three weeks.

The reversing motor saves only eighteen pence a car, for one point eight million pounds. On cost alone, it never pays back. Count the seven hundred grams it saves and it's twenty-nine months. Better, but it belongs to the next platform, not this car.

Every idea gets an FMEA. For the reversing pump, a late spray, because the line drains back, has the highest risk number. But the pump failing outright is the most severe, so it gets a test as well. Deal with high severity first, whatever the number says.

Then the tests. The reversing pump needs five of the eight rungs, ending with a winter on the car. The reversing motor needs all eight, and in practice two winters. The winter test usually sets the date, so start it early.

All fourteen running changes, in four waves, add up to eight pounds sixty-eight a car.

The study ends with one page. The decision goes at the top: approve the washer package now, five pounds fifty-one a car, one point three eight million pounds a year. Then the numbers finance can check, the risks, and what else the team is asking for.

Four asks: approve the washer package; approve waves one to three; fund the feasibility work on composite arms and plastic pivots; and take the reversing motor to the next platform's concept gate.

Then the meeting. 'Why not the reversing motor now?' Give the honest cost answer, then say where its value belongs. 'Isn't four pounds a kilogram made up?' Show where it comes from, and that the decision doesn't depend on it. 'What about drivers without the winter pack?' Name what they lose and how you'll check. 'How will I know the saving is real?' Because you'll track it.

A saving counts only when it shows up in the price the carmaker pays, month after month. Track it, idea by idea. If wave two slips three months, three hundred and forty-two thousand pounds is gone, and a monthly tracker shows it while there's still time to act.

Eight lessons from a windscreen wiper. The job the driver buys can be cheap. Look just past the boundary. Check the baseline. And quick wins can hit the target.