- Project Charter (in.)
- Work Breakdown Structure (pl.)
- Scope Statement (pl.)
- Integrated Project Plan (co.)
Time Planning
In what time frame are we going to execute the project? What milestones are there?
The Time Planning Process deals with estimating the amount of work needed to complete the work packages and activities that were defined in the work breakdown structure.
Input
Process Steps
1. Collecting and reviewing information for the development of the time schedule
Planned content from nearly all knowledge areas goes into the project plan that is developed based on the work breakdown structure. Therefore covering the content precisely and in its entirety is of high importance here.
2. Determining and adding milestones and quality gates
Milestones are project results, which have neither costs, nor running time. They mark the completion of key deliverables. Quality gates include reviewing the delivered results, evaluating existing risks and problems as well as the project progress.
3. Determining and assigning dependencies
Dependencies of work packages and activities need to be identified. Subsequently the dependencies need to be assigned. This step aims at developing a reliable time schedule as well as identifying the critical path.
4. Developing a method to determine total amount of effort
This involves developing a method to estimate the total amount of time and effort needed to complete a given task.
5. Optimizing time schedule
The optimization of the time schedule is an iterative process. The precision and detail of the time schedule depends on the amount of information that is available during planning. The more information is available, the more detailed and precise the plan will become. To be able to react to unplanned events, buffers should always be included in the time schedule.
6. Developing a process to track the actual amount of performed man hours
As a rule either the project manager or the project management office (PMO) is responsible for documenting the data relating to the necessary effort that tasks require to be completed. Persons that deliver the information, are usually team members or team leader representatives.
Output
Please also see knowledge area “Integrated Planning” for overall project planning.
Dependencies of Activities
There are three types of interrelations or dependencies, that determine the order of activities:
- Mandatory dependencies:
- Dependencies that are inherent to the work that needs to be done and cannot be changed. E.g. if you build a house, you must first construct the walls before adding the roof (i.e. ‘hard’ logic).
- Discretionary Dependencies:
- Dependencies that are defined at the discretion of the project team (and may also be omitted). They are usually defined according to the following criteria:
- “Best practices” within a certain field of application.
- A singular aspect of the project that requires a certain sequence of activities, even though there are alternative sequences, which are just as valid (i.e. “preferred” or “soft” logic).
- Dependencies that are defined at the discretion of the project team (and may also be omitted). They are usually defined according to the following criteria:
- External Dependencies
- All dependencies that describe a relation between project activities and activities outside the project. For example the testing period of a software project may depend on the delivery of hardware by an external supplier.
Time Plan
Arrow Procedure Technique
- The time schedule is depicted in shape of a precedence diagram method. Boxes represent activities. These are connected with arrows, in order to show the dependencies.
- Through this, four kinds of dependencies can be distinguished:
- End-Start: The completion of the subsequent activity, depends on the beginning of the prior activity.
- End-End: The completion of the subsequent activity, depends on the completion of the prior activity.
- Start-Start: The beginning of the subsequent activity, depends on the beginning of the prior activity.
- Start-End: The beginning of the subsequent activity, depends on the completion of the prior activity.
Critical Path
Critical Path Method
- The critical path is a set of activities, which determines the total running time of the project. Depending on the duration and work sequence logic, there can be more than one critical path.
- The critical path method is – like the arrow procedure technique – a precedence diagram method. Using a “forwards” and “backwards” analysis, it calculates respectively the theoretically earliest and latest start and end dates for all project activities.
- The difference between the earliest and latest dates is called the total project buffer. The critical path has accordingly either a negative total project buffer time, or a value of zero.
Total Effort Estimation
Total effort estimation can be understood as the estimated value for total amount of resources and time required to complete a task within the project. Effort planning is the basis according to which dates are decided, costs and capacities are calculated and business cases are developed. An estimation becomes possible, through dividing the project into many different parts and work packages. The smaller the work packages are, the more precise the estimation can be. Problems arise usually through:
- A lack of technical knowledge in people that carry out the planning
- A difference in productivity between the project team members.
- A disregard of costs arising from the project (e.g. costs of a project office or employee training)
Estimation methods
Analogous estimation
The work packages of the current project are compared to historical data of already completed work packages. Based on this information the effort is calculated. 
Expert Judgement
Expert judgement is the most common estimation method nowadays
| Single estimation | Group estimation |
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The project manager is responsible for consolidating the single estimates into one overall project plan
3-point estimation
The 3-point estimation is an estimation of the effort based on a weighted average of the most likely effort, best-case effort and worst-case effort. For each work package three effort estimations are conducted:
- Best-case effort
- Most likely effort
- Worst-case effort
Expected effort= (best-case+ 4*most likely+ worst-case)/6
In addition, it is possible to calculate the probability of occurrence of the estimate:
1. Calculating the standard deviation
Standard deviation= (best-case+ worst-case) / 6
2. Derive probability of occurrence
- Estimate+ / – 1 x standard deviation= 68% probability of occurrence
- Estimate+ / – 2 x standard deviation= 95% probability of occurrence
- Estimate+ / – 3 x standard deviation= 98% probability of occurrence
