Building contract projects
Before
The contractor was running four sites at once: the Vanak residential tower, the Karaj housing blocks, the Qom school, and the Shahr-e Rey shed. Each site had a progress sheet that the resident engineer sent to head office on Fridays. Procurement logged rebar and cement from the supervisor's message and posted the invoice to a floating materials account, not to a named contract. At month end someone was supposed to remember which site the load had gone to.
The finance office built the Vanak certificate on Thursday night from three separate files: the engineer's percent complete, procurement's invoice list, and the remaining commitment on the project manager's sheet. Those three files did not have to describe the same work. Once, cement delivered to Karaj landed on the Vanak certificate. The client held payment for three weeks. The explanation meeting lasted longer than the drift itself, because nobody could show which contract that load belonged to. The structure subcontractor sent their own certificate separately, and twice the same item nearly got paid again. The client's copy was not the internal copy, because someone had reconciled two spreadsheets the night before.
What was built
Each contract received its own file. The work-breakdown items, physical progress, material receipts, the subcontractor, and the draft certificate sit in that file. The remaining commitment sits next to percent complete. If budget drift passes three percent, the warning appears on the same page before the manager signs, and the certificate stays locked until it is resolved.
An invoice cannot be posted without a contract and an item. A receipt that landed on another site does not appear on this project's certificate. The internal copy and the copy that goes to the client come from one calculation, not from two files reconciled overnight. The structure subcontractor's certificate lives on the same project. If the item is already on the main certificate, the system will not allow a second payment. Photos and minutes attach to the item itself, so a percent complete does not stand without evidence.
A working day
On Monday the Vanak engineer records the structure at 62 percent from the site and attaches the photo of the eighth-floor slab to that item. The same day procurement posts the rebar invoice to the Vanak contract and the structure item, not to the Karaj housing. If they pick the Karaj site by mistake, that amount does not appear on the Vanak draft. On Tuesday the project manager opens the draft. The remaining commitment sits beside 62 percent, the Karaj cement is not on the list, and the budget warning is off. The subcontractor sends their certificate the same week and the duplicate row is rejected.
On Thursday head office reads the week's drift for all four sites. The Qom school is two percent ahead of the cost plan, and the Shahr-e Rey shed is waiting on the sandwich-panel purchase. The meeting with the client starts from that page. Nobody sends a file, and nobody pastes spreadsheets together the night before. The client sees the table the technical office is talking about.
The result
The next certificate was not a surprise. The client's payment comes from a table that both the technical office and the site can see. The Karaj cement dispute did not happen again, because a receipt's destination cannot be separated from the certificate's destination. The second payment to the structure subcontractor was closed too, because a duplicate item no longer gets through.
The four sites still run together, and coordinating them still takes work. Cost, commitment, and physical progress are one picture. What remains to argue about is quantity and rate, not which spreadsheet was right. Each contract has its own file, its own purchases, and its own certificate.
