More and more tasks are realized in cross-functional projects. The most important differences to tasks that are accomplished in line responsibility are

• changing subjects,
• heterogeneous composition of teams,
• different time-frames, and
• above all temporally limited assignments to a project.

Work packages become more compact and the necessary work time shorter with agile approaches. Eventually, project managers and employees have to work and control many tasks within more or less the same time. However theoretical feasible is not enough, in order to get to a realistic utilization rate.

In the old days, when things were produced in a way that you could take, weigh and measure them, the effects and the necessities were closely linked with one another. Activities in the project that produce and process information cannot be measured in the same way. As a consequence more and more different tasks are assigned to the same person. What is the basis to better assign the tasks?

• Role
  The required role is described by the tasks, authority and the responsibility. Projects manager have the task to lead an initiative, need for this purpose sufficient authority to decide and are responsible for a successful conclusion. Team members receive tasks according to their abilities to create something with the appropriate authorization and the responsibility that goes beyond the correct delivery of results. Neither the individual roles are clarified, nor are the employees characterized sufficiently. This can quickly lead to an overload of the team.
• Expertise
  The most probable is that the expertise will be considered. To what extent the project manager should have technical knowledge apart from its control of project management, can be decided in the respective assignment. If the PM-knowledge is not well developed, the project can fail because of the lack of goals, plans or bad control, but not so much due to missing specialized know-how. On contrary, not existing expertise of the employees has considerable effects. Bad PM-knowledge is then replaceable by the good guidance of the project manager.
• Availability
  Often it is sufficient to be simply available at a certain time, at a certain place. Unfortunately these are seldom the really required know-how carriers, but new or less competent employees. Since the start and the end can only be synchronized with difficulties across project borders, there will be idle running times or overload of the teams, while a project does not find an end the new project generates too fast, too much effort.

Surprisingly, the extent of utilization of the individual employee is not enough considered or not regarded at all. In the absence of resource planning across project borders the actual, temporal load does not become visible. At the same time only a few people know the number of doable, parallel activities. How many projects can be put responsibly in one hand? How many tasks can be realized at the same time? The theoretically feasible number has to be regarded in individual cases. But in principle the timeframe and the setup time times set natural limits that are not related to the capability of the employee.

• Time-frames
  The time-frames of the individual project plans and the necessary expenditures are usually not even considered in the Multi PM cross-functionally. If an employee needs five working days per project for his tasks, he/she cannot take part to more than four projects in a month.
• Setup times
  The setup times between the different projects burden the existing time budget additionally. The related files have to be searched, the current conditions checked and the next steps have to be planned. The more often you jump from one project to another, the less time is available for the actual work.
  Let’s assume that the projects mentioned above (four projects with in each case 5 working days) are switched only once from one day to the other, the respective setup time is hidden in the 5 active days.
  But if we change half daily with a setup time of half an hour, then the change burdens the work with already five hours.
  If we have to leave one project to enter the next one (5 minutes for storing the results and 10 minutes for renewed set-up) the load increases to ten hours.
  If than there is an additional relocation (to another plant or another building), the change can easily cost an hour or more. It results in two hours per day, i.e. forty hours per month. This represents nearly five person days that are missing for the real work.

Bottom line: Estimations become practically feasible, if you select the calculation basis realistically. Without the proper preparation of a project, a reliable planning is only possible with difficulties. For this purpose, besides the actual planning, the role descriptions, the required expertise and the availability of the respective employees as well as their current utilization must be determined. If you ignore the timeframe and the setup times, this will inevitably lead to overload and probably to project failure.