Milestones in project management may often not be met due to several reasons, including:

1. **Poor Planning**: Inadequate initial planning and unrealistic timelines can lead to missed milestones. If the scope or requirements of the project are not clearly defined, teams may struggle to meet deadlines.

2. **Resource Constraints**: Limited availability of resources, such as team members, budget, or materials, can hinder progress. If critical resources aren't allocated appropriately, milestones can be delayed.

3. **Scope Creep**: Changes or enhancements to the project scope without corresponding adjustments to timelines can cause disruptions. If new requirements are added after the project has begun, existing milestones may be affected.

4. **Communication Breakdowns**: Lack of clear communication among team members can result in misunderstandings about responsibilities, timelines, and tasks, which can lead to missed milestones.

5. **Underestimating Complexity**: Projects may face unforeseen challenges or complexities that were not anticipated during the planning phase, causing delays in reaching milestones.

6. **Dependency Delays**: Milestones might be dependent on the completion of other tasks or deliverables. Delays in these dependencies can have a cascading effect on milestone achievement.

Identifying these issues early in the planning and execution phases can help mitigate risks associated with missed milestones.

- What tools do you currently use for project planning and milestone tracking?
- Have you encountered frequent delays in previous projects, and if so, what were the main reasons?
- How do you handle changes in project scope during execution?