Who provides essential information that helps project managers effectively schedule their projects?

The correct answer encompasses all the options, indicating that essential information for project management scheduling can come from various sources, each contributing unique insights.

Subcontractors provide specific insights based on their expertise and familiarity with particular tasks or components of a project. Their input can be crucial in understanding timelines, resource needs, and potential challenges that may affect scheduling.

Records of similar past projects serve as valuable benchmarks. They allow project managers to draw lessons from previous experiences, assess time frames for comparable tasks, and anticipate potential issues that could arise. This historical data can improve accuracy in planning and scheduling for new projects.

Expediters play a role in ensuring that materials and resources are delivered on time, thus influencing scheduling significantly. Their knowledge of logistics and supply chain management helps project managers foresee delays and make necessary adjustments to the schedule.

Drawing from all these sources enables project managers to create more effective and realistic schedules, minimizing risks and enhancing overall project success. Therefore, all these contributors are essential for informed project scheduling.