From a 10-Minute Handwritten Invoice to 90 Seconds

The invoice book is pink, with carbon paper between the pages. On the day I photographed it, the top bill was for two parts, a few thousand pieces of each, with CGST and SGST added and a grand total at the bottom.

I checked every figure: each line, both taxes, the grand total. All of them were right.

That is the part people miss when they talk about paper. Our pilot, the small fabrication unit in Bhosari we wrote about in March, was not careless. He was careful, and careful on paper is slow. The same bill had the HSN column empty, the customer’s GSTIN empty and the amount in words empty. And more of his buyers had started sending handwritten bills back. They wanted a printed one.

In March I wrote that they went digital in three days. That was true: within three days they were making quotations, challans and invoices on their phones. It was not yet fast. This is how that one invoice went from about ten minutes to about ninety seconds, and what happened at each step.

Where ten minutes goes

A four-line tax invoice by hand, as we watched it being written:

Step	Minutes
Customer name, address, date, bill number	1.5
Each line: find the part number and rate in the register, write it	5.0
Calculator: four lines, the total, two taxes, grand total, then again to check	2.0
Amount in words, signature, tear the copies	1.5
Total	10.0

Ten minutes is not much. Five bills a day is close to an hour. Add the challans that arrive with the customer’s material, each one copied into a register, and it is most of a morning, every day, done by the owner or by the one person in the office.

Stage one: the Excel sheet

For the buyers who insisted on print, he kept an Excel template. Typing is faster than writing and the formulas do the sums, so a bill took about six minutes.

But a template is only as right as the last person who edited it. One of his printed bills shows a round-off of −0.12, and then a total that still includes the twelve paise. Nobody noticed, because nobody checks the formula. They check the handwriting.

Stage two: our first screen, which was slower

Our first version was honest and plain, and it was slower than his Excel sheet: about eight minutes a bill. Most of each line was still keyed in by hand.

He switched anyway. Every bill now printed the same way, every buyer accepted it, the record could not be lost, and he never opened the calculator again. Speed was not the first thing he wanted. Being taken seriously by his buyers was.

Stage three: the system remembers, so the clerk doesn’t

The next step was to move what lived in his head, and in the register, into the system. Each part carries its own HSN code, unit and rate. Each customer carries their GSTIN and address. The clerk picks the customer from a list, picks each part, types the quantity, and the tax and totals work themselves out as they type.

That took the bill to about three minutes. Nothing clever happened. We stopped asking people to type what we already knew.

Stage four: nothing is typed twice

By the time a bill is due, almost everything on it already exists. The customer’s challan came in. A job-work order was made from it. A quotation was agreed. So now the bill is made from the challan, with the lines already on it. The form remembers the warehouse and the transporter from last time.

About ninety seconds, and most of that is a person reading the bill before it prints. That part we want to keep.

Job work shows the difference best, because the arithmetic is easy to get wrong. Add 20% to ₹100 and you get ₹120. Take 20% off ₹120 and you get ₹96, not ₹100. The same percentage added and then taken away does not cancel out, and on paper that slip costs ₹4 on every ₹100. On a thin job, that is most of the margin. The system does that arithmetic for him. On paper, the whole chain (challan in, quotation, bill, one round of haggling) took around 36 minutes and a lot of calculation. In the system, about seven.

Stage five: reading the other side’s paper

Bills we raise were now fast. Paper that arrives was not. A customer’s challan or a supplier’s bill still had to be typed in, line by line.

Now he photographs it, or attaches the PDF. In two to five seconds the form fills in: the customer, their challan number, the vehicle, the transporter and every line. He checks it, fixes the odd unit, and saves. A challan that took six to eight minutes to key in takes about a minute and a half. The same works for supplier bills, goods received notes, expense receipts and calibration certificates.

The point is not the AI. The point is that the clerk’s job changed from typing to checking.

Stage six: just ask

The last step is Sārathī, the assistant inside SAMaGRA. It does work, not just conversation. “Add this customer. Here is the GSTIN and the address.” It shows exactly what it is about to save and waits for a yes. It can add a part, a bill of materials or an order. It answers “who owes us money?” and “what is waiting to be dispatched today?” from the same reports the screens use.

It works by typing or by voice, in the language people actually speak on a shop floor. It can only do what the person asking is allowed to do. And it cannot delete anything.

The whole journey on one invoice

Stage	Minutes
Handwritten invoice book	10
Excel template	6
Our first screen	8
The system remembers parts, rates and tax	3
The bill is made from the challan	1.5

These are our estimates from watching the work, not stopwatch readings. We are timing them properly on our next visit and will update this post with what we measure.

The two month-end questions

Two requests from customers used to cost him more than any bill.

How much of my material is left? Most of his work is job work: the customer sends the raw material, he makes the parts. At month-end the customer asks for the closing stock, and not in kilos. In parts. Say 100 kg of their sheet is still on his floor. The customer does not want to hear “100 kg”. They want to hear “you can still get 500 parts from it”.

He kept no record of how much material each part takes. So he went out to the floor to see what was really there, then worked through the customer’s own Excel sheet, part by part, to turn kilos into pieces. Four to five hours, every month-end.

Now the system already knows what came in on each challan, what went out as parts, and how much material each part uses. The part-wise report takes two or three seconds, and he shares it with the customer straight away.

Can you send me the ledger? Everything bought and sold between him and that customer: every bill, every purchase, every payment. Putting it together meant going through every transaction by hand. Three or four hours one day, three or four the next. And when he finally sent it, there was always the same doubt: have I missed something?

Now the ledger is one screen, with purchases and sales together for anyone who is both a customer and a supplier. It is made from the same entries the bills are made from, so a bill that exists is a bill that is in it. The hours went. So did the doubt.

What the time is for

At five bills a day, ten minutes down to ninety seconds gives back about 18 hours a month on invoices alone. Add the challans and supplier bills and it comes to roughly four working days a month.

An owner asked us the obvious question: my clerk is paid either way, so what is that worth? By itself, nothing. It is worth something when it goes into work that has been waiting. The calls to customers who are late paying. The quotation that goes out the same day instead of next week, before the buyer has picked someone else. A look at whether a part quoted two years ago still makes money at today’s steel price. The material that has been sitting at a subcontractor for months.

Or the owner simply stops doing the clerk’s work at eight at night.

What the next shop gets

Our pilot walked through every one of these stages with us, one at a time, over months. He paid for the learning, and the product is better for every rough edge he reported.

The next shop starts at the end. The first week goes into their parts, customers and rates, much of it filled in from photos of last month’s bills. After that, they begin where he is today.

If you run a job shop and still write challans by hand, ask yourself one question: what do you know you should be doing, that never gets done because the day is full of paperwork?