I think that whether a company exceeds the planned value or keeps it depends on how much experience a company has in project management. Basically, we cannot accurately predict what will happen in the future. However, depending on how many documents are written in detail, the previous change experience, errors can be further reduced and the planned values can be better kept.

It is important to have check points to constantly monitor the activity and project level. I believe that it is more likely to go under the planned value because there are usually some obstacles that occur that would inhibit the project to reach its planned value. However, just as Wonbum Sohn said, it is important to properly manage the errors that might occur to have the planned value at a controlled level.

I believe that there are two main factors that determine whether the project will be under or over the planned value such as experience in project management and complexity of the project. The level of complexity can affect how many roadblocks or difficulties can occur throughout the project timeline. In addition, the less experience the manager has with leading a project the more impact these delays can have on the timeline. 

There are a few techniques to regularly maintain the planned value during the monitoring phase: consistently tracking project progress, analyzing the root causes of variances that come up, and keeping up with risk management strategies. Regularly monitoring during the monitoring phase sounds obvious and redundant, but it is quite important. It helps identify problems before they become disastrous and keeps an updated value of the project to compare against the planned value. Now that the value is being consistently updated, it will be a lot simpler to find any discrepancies between the actual value and the planned value. These discrepancies can be positive or negative but it is incredibly important to find their root cause. In the case of a positive discrepancy, finding the root cause may assist in allowing the project to continue whatever caused it (or understand that it was a temporary measure and not something that the project can consistently rely on). For a negative discrepancy, it is even more important to find the root cause to ensure no future problems stemming from this occur. Finally, using tactics brought about by risk management is incredibly important. Being proactive in identifying and mitigating large risks can be incredibly important in maintaining the planned value of a project. By addressing risks that may come up early, one could minimize financial and resource losses on projects.

I think you could try doing a risk assessment and use that to determine how much you should plan each project. This will allow you to to better manage how much time to put into each project. 

When regulating the anticipated value in the monitoring and controlling phase of a project, multiple aspects need to be taken into account. Experience in project management and project complexity affect the chances of staying within the planned budget, but proactive methods are crucial for minimizing possible deviations. One strategy includes establishing routine checkpoints to closely monitor project activities and progress. Project managers can detect possible issues early by continuously monitoring project progress and assessing any variations that occur, allowing them to take corrective action promptly. Using risk management tactics to address potential hazards can help reduce the chances of major deviations from the expected value. Project managers can optimize resource allocation and project schedules by conducting comprehensive risk assessments and adapting project plans accordingly. Proactively monitoring, analyzing, and managing risks is crucial for preserving planned value and achieving project success.