Maintaining cost control system integrity means keeping cost data accurate, timely, and verifiable so management can rely on it to monitor performance and guide decisions. A practice that would totally defeat the purpose directly undermines those safeguards, making reports meaningless and preventing any meaningful control or accountability. When the system’s purpose is entirely defeated, costs can be hidden or manipulated, variances go undetected, and corrective actions can’t be taken—eroding trust in the data and the decisions based on it. The other options align with integrity: improving the reliability of reports makes information more trustworthy, timely reporting ensures issues are addressed promptly, and a neutral impact doesn’t harm the system (though it doesn’t enhance it).

Opportunity cost is the value of the best alternative you give up when you make a choice. It captures the potential gains you miss out on by not selecting the next-best option. In cost decisions, recognizing this helps you compare what you could have achieved with the foregone option versus what you gain with the option you choose. For example, allocating budget to one project means you forgo the potential returns from other projects you could have funded with that money. Sunk costs are past, unrecoverable expenditures and shouldn’t influence current decisions. Book costs are historical accounting values, not the forgone benefits of alternatives. Marginal costs are the additional costs of producing one more unit, not the opportunity lost by choosing one option over another.

Tracking project health by comparing what happened with what was planned is what statusing is all about. After you set a baseline for scope, schedule, and cost, statusing captures current progress and expenditure and compares them to that baseline. This reveals variances in time and money, helps you forecast whether the project will finish on time and within budget, and signals when corrective actions are needed. It also supports clear communication with stakeholders about how the project is actually performing. Documenting team assignments fits more with resource management and staffing. Estimating project duration is a planning activity. Approving changes to scope belongs to change control.

Fully loaded labor cost is the total expense of labor to perform a specific item of work. It equals base salary plus fringe benefits and labor burdens assigned to that item. Base salary is the worker’s regular pay. Fringe benefits are the non-wage compensation like health insurance, retirement benefits, and paid time off. Labor burdens are additional costs tied to employing someone, such as payroll taxes, workers’ compensation, unemployment taxes, and overhead allocated to labor. Adding these components gives the true cost of labor for that item, which is crucial for accurate estimating, budgeting, and cost control. Fringe benefits alone don’t cover the base pay, and labor rates describe a per-unit or per-hour figure that may or may not include all these components. Scope relates to what work is to be done, not its cost.