A project is having issues because the time required to do the smaller work items in the project were underestimated. This could have been avoided by using:

A Work Breakdown Structure (WBS) decomposes project deliverables into smaller, more manageable components, making it easier to estimate the time and resources required for each discrete work package. By breaking down the work thoroughly with a WBS, the project team could have gained a more accurate understanding of the granular tasks and thus provided more precise time estimates.

Quality metrics measure the quality of deliverables, not the time estimation of work items.

A scope statement defines the overall project boundaries and deliverables, but it does not detail the individual work items for granular estimation.

A budget allocates financial resources, which is related to cost, not directly to the detailed time estimation of work items themselves.