The school server hummed in a cupboard beside the sports equipment, where children sometimes left their wet coats.
An had come to collect her son from a parent meeting. The head teacher asked whether Yanchuan, who happened to be with them, could look at a system that kept forgetting which students had permission to take the late bus.
He did not touch the machine.
“What is it supposed to do?” he asked.
A volunteer parent had assembled a scheduling tool from spare hardware and a freely available forecasting package. Teachers entered attendance and activity times. The program suggested which pupils could share a bus without waiting too long. In theory, it would save the school administrative office several calls each afternoon.
In practice, an unreliable network link caused the tool to reuse yesterday’s permissions when a new list failed to load. Teachers had begun printing the current list before dismissal. Some parents thought the printouts meant the software was old-fashioned.
“Those papers prevented us sending the wrong child home,” the head teacher said.
Yanchuan asked who maintained the system. The volunteer was moving away next month. Nobody else knew how its updates were installed, and the school had no budget line for the time required.
“Then it’s not free,” he said.
The head teacher sighed. “I know. But the school didn’t pay for it.”
An stood beside a shelf of deflated footballs and listened without giving him permission to turn the discussion into another project.
The children’s information concerned him more than the scheduling error. A backup drive sat on top of the server, unsecured. The tool stored names, travel arrangements, contact numbers, and occasional notes about who was authorized to collect a pupil. The volunteer had used a third-party development service to help write some of the code, though nobody present knew whether real data had ever been uploaded.
“We shouldn’t inspect private records just because I work with systems,” Yanchuan said. “The school needs its authorized data-protection and IT support to review access and retention.”
The head teacher looked disappointed, then relieved. A simple repair would have been easier to request than a review of an arrangement everybody had accepted because it appeared to work.
Her assistant brought the printed bus list from the office. Every line had been checked by a teacher who knew the pupils. It took effort. It also made the final decision visible.
On the walk home An’s son asked why adults kept using computers to do things they had to check afterward.
“Sometimes checking a suggestion takes less time than doing everything from the beginning,” Yanchuan said.
“Did the bus computer save time?”
“I don’t know. We haven’t measured it.”
“Then why did they say it did?”
An laughed. “That’s a question for the next parent meeting.”
At home she showed Yanchuan her supplier accounts. A spreadsheet had reduced repeated data entry at work, but she still reviewed transactions because one wrong account number could send a payment to the wrong person. She did not call that review a failure of automation.
“The useful part is knowing what I don’t have to do twice,” she said. “The dangerous part is believing it checked the thing I didn’t check.”
That evening Yanchuan wrote a one-page note for the school at the head teacher’s request. It did not include technical instructions for copying data or bypassing access controls. It identified the need to confirm permissions, protect children’s information, make the fallback procedure explicit, and assign someone responsible for maintenance before relying on the server.
He also wrote that the school might decide the system was not worth maintaining.
The head teacher replied the next day. The school would temporarily return to its existing verified lists while arranging a review with its IT provider. Some parents complained that a promising tool had been abandoned.
“It hasn’t been abandoned,” the head teacher told them. “It has been asked to prove it can do the job safely.”
At the factory Ning read a redacted version of Yanchuan’s note, with all school details removed. She said their pilot had the same hidden maintenance question. Who would keep a model useful after the specialists who built it moved to another assignment?
They added a handover milestone: documentation another qualified team could read, a way to stop the recommendations, and an agreed process for correcting data. Guo objected to the extra cost.
“Then price the cost of having a system no one knows how to turn off,” Ning said.
He asked for a comparison. She prepared one.
Yanchuan received an update from Wanjiru that evening. There was still no confirmed movement of Yansheng beyond the annex receiving counter. The official inquiry had not closed. He told An without turning the message into another family meeting.
Their son was drawing a new bridge with side supports. He explained that his teacher had asked the children to write what their designs could not carry.
“Mine can’t carry a person,” the boy said.
“That’s an important thing to know,” Yanchuan replied.
The boy looked at him with the patience children reserve for adults who misunderstand an obvious point.
“It’s made of cardboard.”
At bedtime An put the printed bus list in a folder, ready for the next day. The quiet server remained at school, powered down pending review. Nobody had lost the ability to get home.
Yanchuan had spent months arguing that a report’s attractive number must not erase the conditions beneath it. Here the conditions had names and small school bags. The cost of checking them belonged in the plan.
He added a final requirement to the pilot’s handover section: name the person responsible for the system, a trained substitute, and a schedule for checking that the fallback still worked. In his note to the school he left a blank for the administrator assigned to verify the backup each Friday.
Neither document would keep a server running by itself. Someone would have to accept the responsibility written on the page.