As soon as it was light, Chen Hao squatted by the window frame of the No. 3 living area, holding a tape measure in his hand, his brows furrowed.

"Seventy-nine point three," he said, throwing the ruler on the ground. "The wall opening is only seventy-eight."

Susan stood to the side, four windshield windows that had just been removed piled at her feet. She reached out and touched the edge of the window frame, then looked up at the narrow gap: "It was almost impossible to squeeze it in."

Carl walked over from the other end, carrying the last panel on his shoulder, setting it down with a dull thud. "Didn't you say we tested the size for each batch?"

“We tried it.” Chen Hao stood up and clapped his hands. “But we tried assembling it on the ground, not pressing it against the wall.”

Nana had already brought up the 3D model and projected it onto the wall. With a light tap of her finger, the screen switched to a comparison image: "The design allows for an error of ±0.5 millimeters, with a total of six processes, and the maximum cumulative deviation can reach 3 millimeters."

"So we were almost there with every cut, and in the end, we were just short enough to make a small gap," Susan sighed.

Chen Hao bent down and picked up a piece of scrap material. He turned it over and saw that it still had a qualified label on it. "The problem isn't with which cut it was made, but with how we felt it was 'almost the same' at every cut."

He turned and walked toward the workshop, his steps slow, but no one dared to stop him.

Susan caught up: "What do we do now? Redo it?"

"Stop for now," Chen Hao said. "Stop shipping all those that haven't been installed yet."

Inside the workshop, the cutting team was preparing to start work. Seeing them enter, their movements slowed down.

Chen Hao walked to the bulletin board, tore off the old slip of paper that read "Daily Output: 6," and replaced it with a new one. It only had two words written on it: **Rework**.

"Of the ten panels we made yesterday, four have been installed, but we've taken them all back down," he said. "The remaining six panels will all be remeasured and graded according to their actual dimensions."

Someone muttered quietly, "It's only a centimeter off, can't we just saw it off a bit?"

"Saw it off?" Chen Hao turned to look at him. "You're sawing off the rubber rebound layer. It won't be compressed properly, and it'll leak after a couple of gusts of wind."

The man shrank his neck.

Nana stepped forward, and a set of data appeared on the screen: "According to database records, in extreme environments, a gap of 0.2 millimeters in the sealing structure can allow airflow to pass through. Currently, many windows have partial gaps in their sealing."

"In other words, even if you manage to squeeze it in, it won't block the wind," Susan added.

“Yes.” Chen Hao nodded. “We’re not installing windows right now, we’re saving lives.”

Carl squatted in front of an assembly table, repeatedly bending a piece of rubber in his hand. "The tire skin thickness varies, so the pressed-out tires will naturally look different."

“So we have to screen them,” Nana said. “I suggest dividing the materials into three grades according to thickness to match window types with different pressure requirements.”

“Then let’s divide them.” Chen Hao made the decision. “Susan, you take the lead in reclassifying them; Carl, you’re in charge of the fitting group. Use the empty wall frames as the standard, and try each one out before finalizing the design.”

"Do we still need to record working hours?" someone asked.

“Today’s output isn’t counted,” Chen Hao said. “We’re only counting the corrections. Whoever does the best rework will be prioritized for production tomorrow.”

The air went still for a moment.

Then the cutting team quietly put away their tools and started moving materials.

Susan pulled out a pile of semi-finished products and measured and recorded them one by one. She found that some rubber rings had skewed cuts, and some were uneven in thickness, which was obviously because the blades were dull and still being used.

"This isn't production, it's just makeshift work," she muttered, throwing a batch of substandard products into the waste bin.

Carl and the two men set up a makeshift frame against the wall and tried to install the first repaired window. It still got stuck.

“Too high.” He touched the top edge. “Reduce it by two millimeters.”

"Don't cut it," Nana suddenly said. "I suggest adjusting the pressure curve of the pressing fixture so that the frame has room for fine-tuning during installation."

"You mean, let it shrink a little on its own?" Karl looked up.

"Yes." Nana brought up the parameter diagram. "Preset 0.8 mm compression margin, automatic fit during installation."

“That sounds like a hoax,” Carl frowned.

“But it can work,” Nana said. “Seventeen similar cases have already verified the effectiveness of this mechanism.”

Chen Hao listened for a while and then suddenly laughed: "We always thought that everything should be perfectly sealed, but it's actually better to leave some room for maneuver."

“The key is knowing where it’s breathing,” Susan interjected.

"Therefore, every window must pass three tests before leaving the factory." Chen Hao held up three fingers. "First, measure the dimensions; second, test the fit; and third, conduct a dynamic pressure test."

"Another step?" Karl looked distressed.

"If you don't want to get up in the middle of the night to plug the leak, you have to add more," Chen Hao said. "You think it's too much trouble now, but it'll be even more troublesome when the wind blows in."

Before noon, the first batch of revised windows was completed.

Carl personally pushed it to the wall and slowly pushed it in. This time, there was no force; instead, it slid in steadily, making a soft click when it reached the bottom—like a lock returning to its position.

"We made it in." He breathed a sigh of relief.

Susan reached out to check the gaps around her, running her fingertips around the area, but didn't feel any obvious gaps.

"It looks good," she said, "but it still needs to be blown on."

They brought in a blower, plugged it in, and started blowing it hard into the window cracks.

At first, nothing happened. Thirty seconds later, a faint whistle came from the bottom left corner.

“There’s a leak,” Susan immediately pointed.

Carl lay down to take a look and found that the fixing point of the traction strap had shifted, causing the rubber strip to be partially suspended.

"The clamp pressure is still uneven," he said. "It's too much pressure on one side and not enough on the other."

“Change it,” Chen Hao said. “Replace the clamp springs and adjust them synchronously on both sides.”

The second round of fittings began at 3 p.m.

This time they used a new clamp that provides real-time feedback on the pressure during pressing. After each panel was completed, it was tested on an empty frame, and the deviation value was marked.

After the third fan was installed, it was tested for ten minutes and there was no air leakage.

The fourth door, the same.

"Done?" Carl looked at the readings on the dashboard.

"For now," Chen Hao said, not letting his guard down. "Let's try two more doors."

The fifth door vibrated slightly, but the seal was intact.

The sixth panel meets all the requirements.

"That's fine." Susan wiped her sweat. "As long as you maintain this standard, there shouldn't be any major problems."

Chen Hao walked to the control panel, opened the rework log, and wrote the first entry: **First batch of corrections completed, six doors qualified, four doors awaiting secondary adjustments.**

He looked up and asked, "How many more batches of materials are there?"

“Enough to make thirty panels,” Susan replied.

"Then not a single one can be wrong."

Nana updated the production manual, adding three mandatory procedures:

I. Materials shall be classified and labeled before being put into storage;

2. Pre-installation testing must be completed for each window before it leaves the factory;

Third, dynamic stress testing is included as a mandatory quality inspection item.

“This will be the rule from now on,” Chen Hao said. “Anyone who skips a step will have to go back and relearn it.”

As night fell, the workshop lights were still on.

The first batch of corrected windows were renumbered and neatly stacked in the installation area. A warning tape was put up in the installation area, with red stickers on it: **Installation prohibited without testing.**

Susan was taking inventory of the rubber materials, stacking them separately according to thickness. Beside her was a newly made quick reference sheet outlining the applicable scope of each material category.

Carl squatted by the assembly table, wrench in hand, adjusting the screws of the clamps little by little. Every time he tightened one, he would shake the frame with his hand to listen for any looseness.

Nana stood in front of the terminal, the screen scrolling with new process parameters. She synchronized the data every few minutes to ensure all equipment received the latest instructions.

Chen Hao sat on his toolbox in the corner, holding a repaired window corner piece in his hand. He examined the seam from all angles, then suddenly asked, "Why did we insist on getting it perfect right away?"

Nana turned her head: "Because humans tend to believe in the existence of perfect solutions."

“But nothing is perfect,” Chen Hao smiled. “It’s all built up.”

He stood up and threw the piece of scrap into the recycling bin.

"We'll continue tomorrow."

Carl looked up: "Are we really going to have two shifts?"

"Otherwise what?" Chen Hao said, "Finish the revisions sooner, and get a good night's sleep sooner."

Susan finished sorting the last stack of materials and labeled them.

“I’ll be there at six tomorrow morning,” she said.

“I’m on the night shift,” Carl said, “and I’ll keep an eye on the fixtures while I’m at it.”

Nana's voice rang out: "A new shift schedule has been generated, and Chen Hao is now a mobile shift worker."

Chen Hao didn't speak, but walked to the bulletin board, picked up a marker, and wrote below the progress bar:

Repairs completed: 6

[4 pending]

Tomorrow's goal: Clear all targets.

He put down his pen and stretched his wrists.

The wind outside the workshop grew stronger, making the corrugated iron shed rattle.

He walked back to the data table, opened the ledger, and prepared to record today's summary.

The pen tip just touched the paper—

"Wait a minute," Susan suddenly said.

She was holding a window that had just been measured, her finger slowly moving along the bottom edge.

"It's a bit loose here."

Chen Hao immediately got up and went over.

She pointed to a fixing point in the lower right corner: "The straps look tight, but the frame is a bit warped."

Carl chimed in, "Was the gasket not pressed flat?"

Nana pulled up the test results: "The pressure value here is 12% lower than the standard. It is recommended to re-press it."

Chen Hao squatted down and pressed the area with his hand.

Sure enough, there was a slight tremor.