Projects need to have all their work completed to a certain quality. This quality must be evidenced. However, particularly in physical construction, there is is often no easy way to check whether some construction was done correctly or to specification after it has been completed.
Concrete pours cover the steel reinforcement, refilling excavation covers the laid cables or pipes. It can be expensive and time consuming to check that these covered areas were actually placed according to engineering standards or according to the drawings, design or scope documents.
Most projects I have been involved with, especially those that included physical works, included hold points whereby the contractors had to have their works witnessed before proceeding.
This would include things such as a hold point for the spacing of steel reinforcement. Where the construction inspector, project manager, or similar experienced and authorised person must inspect and usually measure the reinforcement size and spacing after it is positioned but before the concrete is poured over it.
It is important that the project scope (including the construction drawings) specify particular hold points for the works. These hold points must be clear, specific, and enforced.
You as the project manager must ensure that the construction at these hold points are inspected (or delegate that responsibility). You should require a signature by you or the construction inspector or similar at each hold point for approval to proceed (or even for payment to be made). Don’t just sign or let these be signed after the work is complete, they need to be witnessed.
If the hold points are not enforced, then contractors can get used to them not being enforced, and may progress without inspections.
I believe you should enforce inspections at hold points right from the start, and continue through the project. This ensures that the construction work is consistent in its quality. Inspecting at hold points right from the start also allows you to spot potential problems with contractor workmanship or quality procedures early. It also allows you to check that contractors are following the specifications (or even know and understand the specification details).
For example, some contractors may increase the spacing of their reinforcement above the specified spacing as a matter of habit to save money, or simply because some of their staff are inexperienced. By spotting this early you can get this corrected before it becomes an issue.
Enforcement of hold points does not just apply to physical works projects. Most projects need hold points in place for decisions to be made at certain points, or for evidence of progress to be recorded.
In support of hold points, I also find it is good practice to take photos of the works at these hold points, and to file these with the date and time recorded. Even better, note with those photos (or on the photos) the measurements or similar that were signed off for those hold points. Also make sure you store those photos properly in the project files or project document management system. They may be needed in future to evidence that checks were made, especially of there is a failure at a later date (which can sometimes be years later).
Set hold points for your projects, in the scope documents, specifications and especially on the drawings. Enforce inspection of these hold points, to ensure the scope and quality requirements are met.