Predictive project management - Tools for predictive planning

Learning Outcomes

After reading this article, you will be able to identify the core tools used in predictive project planning, explain how to create and use key planning artifacts (such as the work breakdown structure and network diagram), and apply schedule and cost estimating techniques. You will also understand how these tools interact to create integrated, controllable plans, giving you the practical basis to answer PMP questions on predictive planning.

PMP Syllabus

For PMP, you are required to understand the main tools and methods that underpin predictive planning. Ensure you focus your revision on:

• Defining and decomposing project scope using the work breakdown structure (WBS) and WBS dictionary.
• Creating activity lists and identifying dependencies for sequencing with network diagrams.
• Applying key estimating techniques (analogous, parametric, three-point) to schedule and cost planning.
• Developing a schedule using the critical path method and bar charts.
• Setting and using baselines for scope, schedule, and cost to control performance.
• Integrating planning artifacts to create a comprehensive project management plan.
• Recognizing how planning in predictive projects supports control, change management, and stakeholder communication.

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. Which tool is used to visually decompose project scope into manageable deliverables in a predictive project?
2. What two primary types of relationships are shown in a schedule network diagram?
3. Which estimating technique uses three points (optimistic, most likely, pessimistic) to improve accuracy?
4. What is the main purpose of setting a project schedule baseline?

Introduction

Predictive project management relies on thorough up-front planning to organize, estimate, and schedule project work before execution begins. Creating detailed, documented plans is central to controlling changes, managing risk, and delivering on commitments. This article focuses on the practical methods and tools that enable predictive planning, allowing you to construct integrated project plans that support effective control and delivery.

Overview of Predictive Planning

Predictive planning establishes a comprehensive map for the project's execution before significant work starts. The approach assumes that project scope can be defined with reasonable accuracy, and that subsequent changes to scope, time, or cost will be tightly managed via defined processes.

The key tools described here—including the work breakdown structure (WBS), activity lists, network diagrams, and baselines—are used together to create an integrated project management plan.

Key Term: Work Breakdown Structure (WBS) A hierarchical representation that decomposes project scope into manageable deliverables and sub-deliverables, forming the basis for detailed planning and estimation.

Key Term: Network Diagram A graphical representation showing the sequence, dependencies, and logical relationships among project activities; used primarily for schedule development and critical path analysis.

Key Term: Baseline An approved, fixed version of the schedule, cost, or scope plan used as a reference for measuring actual project performance and controlling changes.

Key Term: Three-Point Estimating An estimation technique that considers optimistic, most likely, and pessimistic scenarios to calculate a realistic range for activity duration or cost.

The Work Breakdown Structure (WBS)

The WBS is the primary tool for decomposing and visualizing project scope. It divides the project deliverables into progressively smaller components, called work packages, that can be scheduled, estimated, assigned, and controlled. A typical WBS is created as a tree diagram, but can also be shown in tabular or outline form.

Benefits

• Clarifies what needs to be done and avoids missing deliverables.
• Breaks down complex work into manageable pieces for estimating and assignment.
• Serves as a communication tool with team, management, and stakeholders.

Key Term: WBS Dictionary A document providing detailed descriptions, acceptance criteria, resources, and dependencies for each work package listed in the WBS.

Activity List and Sequencing

After deliverables are broken down in the WBS, each is decomposed further into activities (tasks) required for completion. The activity list forms the basis for estimating, scheduling, and sequencing work.

Activities are linked using dependencies:

• Mandatory (hard): Essentially required by the nature of work (e.g., the base must be poured before framing a building).
• Discretionary (soft): Preferred based on best practice but not strictly required.
• External/Internal: Based on factors outside or inside the project's direct control.

Sequencing is visualized with a network diagram, which maps each activity node and its dependencies.

Creating the Project Schedule

The schedule is developed by combining the activity list, durations, and dependencies into a timeline using bar charts (Gantt charts) and network diagrams.

The Critical Path Method (CPM) is the primary analytical tool. It identifies the longest sequence of dependent activities (with zero float), indicating the shortest possible project duration and the set of tasks that cannot be delayed without affecting project completion.

Bar charts provide a visual overview of the entire timeline but do not highlight dependencies as explicitly as network diagrams.

Estimating Techniques for Predictive Planning

Accurate estimating is essential for setting realistic schedules and budgets. Common techniques include:

• Analogous Estimating: Uses historical data from similar projects to estimate duration or cost; quick but less accurate.
• Parametric Estimating: Applies statistical relationships based on unit quantities (e.g., cost per square meter, hours per module).
• Three-Point Estimating: Improves accuracy by averaging optimistic, pessimistic, and most likely estimates.

Example Formula (Three-Point, Beta Distribution)

$(O + 4M + P)/6$

where O = Optimistic, M = Most Likely, P = Pessimistic

Performance Measurement Baselines

Baselines are approved plans against which actual project performance is measured. In predictive projects, common baselines include:

• Scope Baseline: The approved version of the WBS, WBS dictionary, and scope statement.
• Schedule Baseline: The approved, time-phased project schedule.
• Cost Baseline: The time-phased budget for the project lifecycle.

Baselines are established during planning and formally changed only through defined change control procedures.

Integrating the Planning Tools

Each of these tools—WBS, activity list, network diagram, estimates, and baselines—work together to create a comprehensive project management plan. This integrated plan is used to:

• Assign responsibilities and resources to tasks.
• Communicate expectations and manage stakeholder engagement.
• Monitor performance and control changes systematically.
• Support informed decision making.

Worked Example 1.1

A project to construct a small office building is beginning the planning process. The project manager creates a WBS that breaks the scope into groundwork, framing, roofing, electrical, and interiors. Each is divided further into work packages.

Next, the project manager identifies the activities for the "framing" work package: order materials, receive delivery, assemble walls, erect roof trusses, and inspection.

Using the network diagram, activities are sequenced to show dependencies:

• "Order materials" must finish before "receive delivery" can start.
• "Erect roof trusses" cannot begin until "assemble walls" is complete.

For each activity, durations are estimated using three-point estimating:

• Most likely: 5 days; Optimistic: 3 days; Pessimistic: 7 days

Beta estimate: (3 + 4×5 + 7) / 6 = 5 days

The project manager then develops the schedule, calculates the critical path, and sets this as the schedule baseline.

Answer: This example integrates WBS, activity sequencing, estimating, and baseline setting—allowing the project manager to control schedule, cost, and scope performance.

Exam Warning

A common error on the PMP exam is confusing the purpose of the WBS (scope decomposition) with the activity list (work sequencing). Remember: WBS shows deliverables, while the activity list details how the work is performed.

Revision Tip

Before answering scheduling or change questions, quickly clarify in your head whether the question is asking about planning (setting expectations) or controlling (measuring performance and making adjustments).

Key Point Checklist

This article has covered the following key knowledge points:

• The WBS systematically decomposes project scope for effective planning.
• Sequencing activities and representing dependencies with network diagrams supports critical path analysis.
• Accurate estimates use techniques like analogous, parametric, and three-point estimating.
• Performance baselines for schedule, cost, and scope establish standards for control.
• Plans and baselines can only be changed through defined change control processes.
• Each planning artifact (WBS, activity list, network diagram, baselines) plays a distinct role in predictive planning.
• Integrated planning simplifies control, communication, and stakeholder alignment.

Key Terms and Concepts

• Work Breakdown Structure (WBS)
• WBS Dictionary
• Network Diagram
• Baseline
• Three-Point Estimating