The most important part is the missing one

After weeks of discussions and long negotiations, you received the order for your new project. You struggled for weeks to supply the materials for this project, which you agreed upon under challenging deadlines and budget conditions due to the competitive environment. Meanwhile, you were delayed in starting production for various reasons. You worked long hours to process, weld, clean, and paint hundreds of parts... As the delivery date was getting closer, you started assembling the hundreds of prepared parts. Just hours away from delivering your project and taking a breath of relief, your phone starts ringing. The head mechanic says that a tiny part is missing and it has stopped the production, and everything suddenly turns into a nightmare.