Open 1 order on the admin screen, look at it, close it, open the next. Over 2 days I did that 600 times. What I was counting was how many orders had the wrong total. Before I had finished counting, I took what I had counted, estimated the whole from it, and told the owner it was about 150. It was 38. That is what I am writing about today.
What had happened, first. In KAZENA Order the guest orders from their own phone and the order goes straight to the kitchen. We made it so the quantity can be changed after that. A guest who pressed 3 tells the staff, and the staff change it to 2. A change like that happens a few times a day.
The day's sales total was reading the quantity from before the change. An order holds 2 quantities: the one entered first and the one it became. The part that produces the total was reading the earlier one. So on any day with a changed order, sales come out high. Fixing that part took 2 hours. What was left was the days we had already closed.
The owner asked 2 things. How many are there, and how much too high in total. Neither can be answered without counting the past. I opened the admin screen and started counting.
The counting went like this. Open 1 order and you can see its change history. Find the ones where the quantity moved, then look at which quantity the order's total was built from. 15 to 20 seconds per order. Across the 3 stores there were 5,120 orders in those 2 months.
In 2 days I got through 600. 18 of them were affected. 18 in 600 makes about 150 in 5,120. I did that arithmetic and said it on the phone. Which means I spoke about the 600 I had counted and the 4,520 I had not in the same tone of voice.
I counted it again with a read. The order, the quantity's change history and the day's total, read together as 1 question. It took 1 hour to write and 4 seconds to answer. 38 orders, 1,870 pesos too high in total. The 2 days I spent counting by eye produced nothing next to that 1 hour. That is what I thought at the time.
The reason the estimate came out at 150 was not the arithmetic. It was that the affected orders were not spread across those 2 months. Only 1 of the 3 stores used the quantity change at all, and that store used it in a burst over 6 days when it was unusually busy. The 600 I opened were the top of a list sorted newest first, and those 6 days were in there. I looked at the most unusual week and spoke about 2 months.
The first read I wrote was wrong too. Its first answer was 212. The condition was also catching orders whose quantity had been changed and then put back to what it was. Those have the right total, so they are not ones to fix.
The only reason I caught that is that I had kept the 20 orders I had checked by hand. Matching the read's answer against those 20, some did not agree. I corrected the condition, it came to 38, and matching again, all 20 agreed. The 2 days of counting by eye were useless for producing the answer and necessary for checking it.
I called the owner back to correct the number. 3 days after I had said 150. I had been wrong on the high side, so they took it as lighter than they had expected. Wrong the other way, the same call is heavier. Less than the being wrong, the mistake was saying an estimated number in the same voice as a checked one.
We changed 2 things. One is where the total reads its quantity from, and that was the 2 hours. The other is that the question now sits in the admin screen. Orders whose total does not agree are listed with the date, the number and the difference. The owner can open it and count it themselves. It says 0 now. I passed it to the engineer on the KAZENA side as well. The same question comes up on their side, so what carries over is the shape of it: do not make a person count.
What I had confused was what counting is for. When a person counts by eye, the rule drifts while they count. I cannot claim I read the history the same way at order 200 as at order 500. And if you do not finish, the rest becomes a guess. A read returns the same answer to the same question. How many are there was a question to put to the data, not to a person. These days I do not answer that question out loud. I open the screen and we look at it together.