We're not saying that a project plan cannot include more than 1000 task items and more task links. If we can spend enough efforts to plan the thousands of tasks and links well, we will get a “perfect” project schedule for tracking and re-scheduling.

It seems that this "perfect" plan can help us automate the heavy re-schduling work. After the date of a task is modified, the successors will also be changed according to the link constraints. So if one task needs to be adjusted, we just need to change one, the app will follow the link constraints to do the rest well.

Sounds good, but wait, let’s think a little more about this “perfect” approach.

Why we need to specify the start, finish date, the resource, the cost and the links for the tasks, why we do not just plan the work easily (like managing tasks in a simple to-do list). As we are using project schedule to guide the project team to execute the project (when, why, who and how much, etc.), to track the task progress with the team and to re-schedule if needed. The project team needs to follow the schedule for daily work and needs to update the status to make the fresh plan be reality for the coming days.

• Is the plan convenient enought to update task status when reviewing with the team?
• Is the management cost acceptable to change something if need to broke the link relationship? (for example especially when you find you have to spend hours for just changing one task schedule, as there are many tasks linked, change one will impact many)
• We can trust the app, but can we trust the result of re-scheduling? You changed one task, and the app does well to change the date of linked tasks correctly, but do you think after the tasks be re-scheduled automatically according to the links, the new plan will be the right one (proper resource allocation, duration, cost, and etc.)?
• It will be super time-consuming to create a perfect link, which can make sure that every thing will be good after it takes effect - the updated plan will still satisfy the balance of resources, keep low cost and short duration. The reality is that most of the time, we still need to check the result manually after the “perfect” link takes effect.
• Is the schedule is a clear map in your mind? And can your team members to get started easily? If the project manager and project members have no idea about the upcoming tasks, (as we have a “perfect” and complicated schedule document, we have to check it before taking actions every day. We will have no idea what will happen if need to change something, we have to check the document and have a long meeting with the team for any unexpected change.) how the team can face risks and changes.
• Is it a good practice to see too many tasks together on an iOS device? (Although QuickPlan is the most smooth Gantt chart app, there is no performance issue. However to navigate through a list with thousands of items is still not a good practice) or even on a Mac device?

We have some suggestions to organize the tasks well when using QuickPlan

• Organize tasks well in groups, it will help the team to understand easily. Also QuickPlan supports to move tasks in group together
• Organize tasks in the main and sub-projects, make sure NOT to include many tasks in the main and every child projects. (For example, less than 200 in one. Although QuickPlan is still very smooth if thousands of tasks in a single project)
• Depends on the situation, if the project team includes some sub-teams, prefer to plan the work for each sub-team in a child project. This approach is suitable for working with each sub-team separately (especially for a remote organization)
• Try to eliminate the dependency relationship between the tasks across groups. Too many links across groups will make the schedule in a mess.
• Depends on the situation, if the project includes some large phases, prefer to organize the massive project phases in sub-projects.
• If possible and if the project is not that complicated, avoid to use task link, organize the tasks well in groups. Moving task groups for re-scheduling is more intuitive than depending on task links. (As described in preceding, even using task links to re-schedule, we will still need to check if the new schedule is the proper one)
• Pay attention to task links, especially for the long task link chain. We do expect the link constraints can help us when changing task date, but will we feel good after changed one task date without checking all the linked tasks? The app can change the time of the tasks in the linked chain correctly, but link constraints do not help to balance resource, and do not to fix other issues at the same time. We may find we are in big trouble if need to be reasonable on all aspects for just changing a little. (Of cause for some cases, we have to use very complicated task links)
• If we find that we have to lay out tasks in many outline levels, there may be plenty of space for us to improve the task structure.
• If we find that we have to write long and complicated task descriptions, perhaps we need to consider how to improve other related project documents. A project schedule is just one of the project documents, which is not the replacement of the requirement document or a design document or a testing case document – Let the project schedule focus on scheduling
• Although a long task name is accurate, the long task name may trouble us more when communicating with team members and when reporting. A short task name with a little longer note may be better.
• Leave team members be flexible to manage their very short duration of tasks, and to keep project schedule be accurate but be simple enough.
  
  Give an example, to assign a feature implementation work to a project member. We can create a “perfect” schedule with multiple small tasks (Such as the tasks like “feature xxx coding,” “feature xxx self-testing,” “feature xxx code submit,” “feature xxx …,” etc.) AND links. However, we will find in most of the cases if combining them in one task for a project member will be a better solution.(if the project manager does not want sitting near the members all the days to adjust project schedule as these "perfect" small tasks will cause changes maybe in every one hour)
• Using tools like the Agile Board to manage tasks in very short-term. It will help to make the plan be more clear, simple and real if using other tools to manage the parts which are easily changable.
• We may need to balance the accuracy and management cost. If possible, leave your team members be flexible to manage the details.