6.5 Develop Schedule

The process of analyzing activity sequences, durations, resource requirements, and schedule constraints to create a schedule model for project execution and monitoring and controlling.

The key benefit -> it generates a schedule model with planned dates for completing project activities.

Frequency: throughout the project.

Process	Input	The process	Output	Process
Project Management Plan	Schedule management plan	6.5 Develop Schedule	Schedule baseline	Project Management Plan
	Scope baseline		Schedule management plan
Project Documents	Activity attributes		Cost baseline
	Activity list		Change requests	4.6 Perform Integrated Change Control
	Assumption log		Project schedule	Project Documents
	Basis of estimates		Schedule data
	Duration estimates		Project calendars
	Lesson learned register		Activity attributies
	Milestone list		Assumption log
	Project schedule network diagrams		Duration estimates
	Project team assignments		Lesson learned register
	Resource calendars		Resource requirements
	Resource requirements		Risk register
	Risk register
12.2 Conduct Procurements	Agreements
Enterprise/Organization	Enterprise environment factors
	Organizational process assets

The schedule model is used to determine the planned start and finish dates for project activities and milestones based on the best available information.

Key process steps:

• Define the project milestones,
• Identify and sequence activities,
• Estimate durations,
• Review staff assigned activities,
• Get staff confirmation that the start and finish dates present no conflict with resource calendars and availability,
• Analyze schedule for logical relationships,
• Level resources,
• Approve and baseline schedule.

6.5.1 Inputs

6.5.1.1 Project Management Plan

Include:

• Schedule management plan. (The scheduling method and tool to create the schedule).
• Scope baseline. The scope statement, WBS, WBS dictionary.

6.5.1.2 Project Documents

Include:

• Activity attributes.
• Activity list.
• Assumption log.
• Basis of estimates.
• Duration estimates.
• Lesson learned.
• Milestone list.
• Project schedule network diagrams.
• Project team assignments.
• Resource calendars.
• Resource requirements.
• Risk register.

6.5.1.3 Agreements

Contractual requirements to the project schedule.

6.5.1.4 Enterprise Environmental Factors

• Government or industry standards,
• Communication channels.

6.5.1.5 Organizational Process Assets

Include:

• Scheduling methodology containing the policies governing schedule model development and maintenance,
• Project calendar.

6.5.2 Tools and Techniques

6.5.2.1 Schedule Network Analysis

It is the overarching technique used to generate the project schedule model and employs several other techniques:

• Critical path method,
• Resource optimization techniques,
• Modeling techniques.

Includes:

• Assessing the need to aggregate schedule reserves to reduce the probability of a schedule slip when multiple paths converge at a single point in time or when multiple paths diverge from a single point in time, to reduce the probability of a schedule slip.
• Reviewing the network to see if the critical path has high-risk activities or long lead items that would necessitate use of schedule reserves or the implementation of risk responses.

This technique is an iterative procedure until an acceptable model will be developed.

6.5.2.2 Critical Path Method

It is used to estimate the minimum project duration and determine the amount of schedule flexibility on the logical network paths within the schedule model. Calculation is executed without regard for any resource limitations by performing back and fro pass.

On Wikipedia

• The critical path - the longest path through a project, which defines the shortest possible project duration.
• The total float/schedule flexibility - the amount of time that a schedule activity can be delayed or extended from its early start without delaying the project finish date or violating a schedule constraint. The negative float is calculated when a backward schedule calculation is performed and (once more) it means that the project is late beyond the defined time term.
• Critical path drag - the amount of time that an activity or constraint on the critical path is adding to the project duration. Alternatively, it is the maximum amount of time that one can shorten the activity before it is no longer on the critical path or before its duration becomes zero.

Steps:

• Calculates the longest path of planned activities to logical end points or to the end of the project - critical path. The total float for the path = 0. Negative float - the project execution is beyond the final project term.
• Calculates the earliest and latest that each activity can start and finish without making the project longer (determine "total float").
• The activities on the non-critical path may moved in time inside the total float period.

6.5.2.3 Resource Optimization

The techniques is used to adjust the start and finish dates of activities to adjust planned resource use to be equal to or less than resource availability. A list:

• Resource leveling or resource constrained scheduling (RCS) . Start and finish dates are adjusted based on resource constraints with the goal of balancing the demand for resource with the available supply. The technique can be used when shared or critically required resources are available only at certain times or in limited quantities, or are over-allocated (a resource has been assigned to two or more activities during the same time period), or there is a need to keep resource usage at a constant level. Resource leveling usually causes the original critical path to change.

• Resource smoothing. A technique to adjust the activities of a schedule model such that the requirements for resources on the project do not exceed certain predefined resource limits. The project critical path is not changed and the completion date may not be delayed. The technique use free and total float of activities. It may not be able to optimize all resources. There is need to avoid any delay in activity as it may affect critical path.

The following are a few differences between resource leveling and resource smoothing:

• In resource leveling the project end date may change while in smoothing it does not change.
• In resource leveling the critical path changes (generally increases) while in resource smoothing it does not, and activities can be delayed within their float.
• Generally resource smoothing is usually performed after the resource leveling.
• In resource leveling resources are the main constraint while in resource smoothing project end date is a constraint.
• Resource leveling is used when resources are under or over allocated. Resource smoothing is used when resources are unevenly allocated.
• Resource leveling can be applied to activities on the critical path while in resource smoothing you do not touch activities on the critical path.

6.5.2.4 Data Analysis

Include:

• What-if scenario analysis. The process of evaluating scenarios in order to predict their effect, positive or negative, on project objectives. A schedule network analysis is performed using the schedule to compute the different scenarios (delaying a major component delivery, introducing external factors, such a change in a permit process). The outcome of the analysis can be used to assess the feasibility of the project schedule and prepare reserves and response plans to address the problems.
• Simulation. It models the combined effects of individual project risks and other sources of uncertainty to evaluate their potential impact on the project objects.
  • Monte Carlo analysis. Inputs for the model are using probability distributions (are generated by some probability distribution). The model outcomes are used to build probability distribution for project goals.

6.5.2.5 Leads and Lags

6.5.2.6 Schedule Compression

Techniques are used to shorten or accelerate the schedule duration without reducing the project scope in order to meet schedule constraints, imposed dates, or other schedule objectives. The techniques used for the critical path which total float is zero (or negative if the project delays). Includes:

• Crashing. Shortens the schedule duration by adding resources. Applied to the critical path. Crashing may bring additional risks.
• Fast tracking. Sequence of activities -> parallel (or portion of tasks). May result in rework and risks, additional costs.

6.5.2.7 Project Management Information System (PMIS)

Includes scheduling software -> generates start and finish dates based on the inputs of activities, network diagrams, resources, and activity durations.

6.5.2.8 Agile Release Planning

A high-level summary timeline of the release schedule (3-6 months) based on the product road-map and the product vision. The planning also determines the number of iterations or sprints in the release -> to decide how much needs to be developed and how long it will to have a releasable product based on business goals, dependencies, and impediments.

6.5.3 Outputs

6.5.3.1 Schedule Baseline

The approved version of a schedule model that can be changed only through formal change control procedures and is used as a basis for comparison to actual results. It is accepted and approved by appropriate stakeholders with baseline start dates and baseline finish dates. During monitoring and controlling variances are calculated: baseline against actual dates.

6.5.3.2 Project Schedule

The output of a schedule model that presents linked activities with planned dates, durations, milestones, and resources. At a minimum: start/finish for each activity.

Target model - with a defined target start and target finish for each activity.

Summary, milestone, detail forms of schedule.

Presentation forms:

• Bar charts (Gantt charts). Activities listed on the vertical axis, dates are shown on the horizontal axis, activity durations are shown as horizontal bars places according to start and finish dates. Additional information can be presented.
• Milestone charts. Similar to bar chart, but only main events are presented.
• Project schedule network diagrams.
  • The activity-on-node diagram format showing activities and relationships without a time scale (also referred as a pure logic diagram).
  • Presented in a time-scaled schedule network diagram format (also called a logic bar chart). This presentation shows project network logic and the project's critical path schedule activities.
  • A time-scaled logic diagram. Bars represent the duration of activities with logical relationships.

6.5.3.3 Schedule Data

The collection of information for describing and controlling the schedule:

• Schedule milestones,
• Schedule activities,
• Activity attributes,
• Documentation of all identified assumptions and constraints.

Additional data:

• Resource requirements by time period, often as resource histogram;
• Alternative schedule: best-case/worst-case, resource-leveled/not leveled;
• Applied schedule reserves.

Could include:

• Resource histograms,
• Cash-flow projections,
• Order and delivery schedules,
• Other.

6.5.3.4 Project Calendars

It identifies working days and shifts available for scheduling activities. Available/not available periods of time. Several calendars may be used.

6.5.3.5 Change Requests

6.5.3.6 Project Management Plan Updates

All changes are through change requests.

Components:

• Schedule management plan.
• Cost baseline.

6.5.3.7 Project Documents Updates

Include:

• Activity attributes.
• Assumption log.
  • In duration,
  • Resource utilization,
  • Sequencing,
• Duration estimates.
• Lesson learned register.
• Resource requirements.
• Risk register.