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Alternatives analysis.
Alternatives analysis is used to compare various levels of resource capability or skills;
scheduling compression techniques (described in Section 6.5.2.6); different tools (manual versus automated);
and make, rent, or buy decisions regarding the resources. This allows the team to weigh resource, cost, and
duration variables to determine an optimal approach for accomplishing project work.
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Reserve analysis.
Reserve analysis is used to determine the amount of contingency and management reserve
needed for the project. Duration estimates may include contingency reserves, sometimes referred to as schedule
reserves, to account for schedule uncertainty. Contingency reserves are the estimated duration within the schedule
baseline, which is allocated for identified risks that are accepted. Contingency reserves are associated with the
known-unknowns, which may be estimated to account for this unknown amount of rework. The contingency
reserve may be a percentage of the estimated activity duration or a fixed number of work periods. Contingency
reserves may be separated from the individual activities and aggregated. As more precise information about the
project becomes available, the contingency reserve may be used, reduced, or eliminated. Contingency should be
clearly identified in the schedule documentation.
Estimates may also be produced for the amount of management reserve of schedule for the project. Management
reserves are a specified amount of the project budget withheld for management control purposes and are
reserved for unforeseen work that is within scope of the project. Management reserves are intended to address
the unknown-unknowns that can affect a project. Management reserve is not included in the schedule baseline,
but it is part of the overall project duration requirements. Depending on contract terms, use of management
reserves may require a change to the schedule baseline.
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6.4.2.7 DECISION MAKING
Described in Section 5.2.2.4. Decision-making techniques that can be used in this process include but are not limited
to voting. One variation of the voting method that is often used in agile-based projects is called the fist of five (also called
fist to five). In this technique, the project manager asks the team to show their level of support for a decision by holding
up a closed fist (indicating no support) up to five fingers (indicating full support). If a team member holds up fewer than
three fingers, the team member is given the opportunity to discuss any objections with the team. The project manager
continues the fist-of-five process until the team achieves consensus (everyone holds up three or more fingers) or agrees
to move on to the next decision.
6.4.2.8 MEETINGS
The project team may hold meetings to estimate activity durations. When using an agile approach, it is necessary
to conduct sprint or iteration planning meetings to discuss prioritized product backlog items (user stories) and decide
which of these items the team will commit to work on in the upcoming iteration. The team breaks down user stories to
low-level tasks, with estimates in hours, and then validates that the estimates are achievable based on team capacity
over the duration (iteration). This meeting is usually held on the first day of the iteration and is attended by the product
owner, the Scrum team, and the project manager. The outcome of the meeting includes an iteration backlog, as well as
assumptions, concerns, risks, dependencies, decisions, and actions.
6.4.3 ESTIMATE ACTIVITY DURATIONS: OUTPUTS
6.4.3.1 DURATION ESTIMATES
Duration estimates are quantitative assessments of the likely number of time periods that are required to complete
an activity, a phase, or a project. Duration estimates do not include any lags as described in Section 6.3.2.3. Duration
estimates may include some indication of the range of possible results. For example:
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A range of 2 weeks ± 2 days, which indicates that the activity will take at least 8 days and not more than 12
(assuming a 5-day work week); or
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A 15% probability of exceeding 3 weeks, which indicates a high probability—85%—that the activity will take
3 weeks or less.
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6.4.3.2 BASIS OF ESTIMATES
The amount and type of additional details supporting the duration estimate vary by application area. Regardless of
the level of detail, the supporting documentation should provide a clear and complete understanding of how the duration
estimate was derived.
Supporting detail for duration estimates may include:
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Documentation of the basis of the estimate (i.e., how it was developed),
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Documentation of all assumptions made,
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Documentation of any known constraints,
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Indication of the range of possible estimates (e.g., ±10%) to indicate that the duration is estimated between a
range of values),
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Indication of the confidence level of the final estimate, and
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Documentation of individual project risks influencing this estimate.
6.4.3.3 PROJECT DOCUMENTS UPDATES
Project documents that may be updated as a result of carrying out this process include but are not limited to:
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