The word guarantee appeared in the contract after everyone believed the difficult negotiations were finished.
The customer’s procurement manager had inserted it beside the projected energy reduction. The revision said the pilot provider would guarantee a stated saving during peak-demand periods, subject to ordinary exclusions.
“Which exclusions are ordinary?” Ning asked.
The manager pointed to a general paragraph about equipment faults and force majeure. The pilot’s actual limits were more specific. Its advice depended on the factory’s schedule, approved temperature ranges, sensor quality, available reserve and the authority of operators to decline a suggestion.
“Then list those,” the manager said.
“If we list them all, the guarantee won’t mean anything,” Guo’s analyst replied.
“It might mean something accurate,” Yanchuan said.
They spent the morning separating three claims: the model could generate recommendations under defined conditions; staff could choose whether to implement them; realized savings depended on the decisions and operating circumstances that followed. An output from the first stage could not be sold as certainty about the third without assigning responsibility for everything in between.
Gao was called into the room after lunch.
“Would you permit a contract that penalizes our staff for refusing an unsafe recommendation?” Yanchuan asked.
“No.”
The procurement manager looked offended. He had not intended that result. But the draft allowed it. If the customer refused the recommended action, the provider could argue the saving was lost through the customer’s choice. The factory might then pressure its own operators to accept questionable proposals to avoid a dispute.
“I thought we were buying efficiency,” the manager said.
“You are,” Gao replied. “Not authority over safety.”
They replaced the guarantee with a service commitment the engineering team could meet: data quality checks, forecasts within an agreed horizon, documented recommendations, reports on evaluated outcomes and notice when conditions fell outside the model’s range. Any actual performance guarantee would require a separate agreement about operations, equipment and risk.
The client’s lawyer complained that the new language was less attractive.
“It tells you what we will do,” Chen said. “That is what a contract should do before it tells you what you might save.”
Yanchuan recognized the structure from the acceptance report in Kenya. There, a narrow test had been presented as broad proof. Here, a recommendation tool was nearly becoming a promise about a factory’s entire operation. No one needed to intend a deception for the difference to matter.
He went outside to call An. She was waiting for a supplier to send an overdue reconciliation and was not inclined to sympathize with a difficult client.
“So don’t promise what you don’t control,” she said.
“I know.”
“Then why are you calling?”
“Because the contract is due tomorrow and I don’t know if they’ll accept the smaller claim.”
She was silent for a moment.
“Will you be willing to sign the larger one?”
“No.”
“Then you’ve answered the part you control.”
He did not expect that to feel like help, but it did.
At home that evening Mei read his comparison table. She asked whether their model’s failure conditions had been verified by actual tests or simply carried over from assumptions.
“Some have been tested. Some are operating rules.”
“Mark them differently.”
He did. An operator’s approved limit was not an experimental finding, and a simulation did not prove the system would respond safely to a real emergency.
Mei watched him work.
“You’ve become very good at making a promise smaller,” she said.
“That’s what Guo said.”
“Maybe you should become good at making a small promise valuable.”
The following week the client accepted the revised contract in principle. Guo’s firm would pay for extending the pilot to a second production cycle. The factory retained the authority to stop recommendations. The report could show savings only with the applicable operating conditions, the number of suggestions declined and the interruptions excluded from evaluation.
It was not the contract the commercial team had imagined. It was a contract people in the factory could explain to one another.
Amina called on Friday with news from the technical review abroad. Corrective testing was being planned with the auxiliary cooling arrangements explicitly documented. The operator would decide when the installation was ready. The investigators had not reported a new confirmed sighting of Yansheng.
“Will the next test have all the loads?” Yanchuan asked.
“The agreed scope will be stated before it begins,” she said. “I won’t tell you it has passed before it has happened.”
He smiled at the familiar firmness.
“I’m not asking you to.”
“You were thinking it.”
“Yes.”
They spoke about the workers who would conduct the test and the need not to rush them because outside people wanted a number. Amina had insisted that a worker representative could question any proposed boundary that changed the tasks or safety conditions of the crew.
When the call ended, Yanchuan opened his brother’s first message once more. Can these two summaries both be right?
He finally knew an answer precise enough for the work: under different defined boundaries, both totals might be correctly calculated; they could not establish the same full-service promise without accounting for what had been excluded.
He still did not know where his brother was.
At the pilot’s signing, Gao asked whether everyone had read the conditions, not merely the projected benefits. They had. Ning initialled the technical schedule. Chen signed for the engineering firm. The customer’s manager signed after crossing out a stray sentence left over from the earlier guarantee.
Guo watched them and said that the agreement looked less ambitious on paper than the first proposal.
“Perhaps,” Yanchuan answered. “Ask me again after the first hot week. The numbers are honest now, but the equipment still has to perform.”
Outside, the afternoon was cooling. In the equipment room, the fans kept running, carrying away heat that no contract could make disappear.