Flow-Based Projects: Kanban Boards and Work-in-Progress Limits

PMBOK v8 Definition

Flow-based projects, such as those that use kanban boards, use charts to limit the amount of work in progress (WIP). These projects adopt techniques from flow-maximizing approaches such as the Kanban method (a visual workflow management method to limit work in process based on lean principles and focusing on continuous delivery without overburdening the team) and the theory of constraints (a management philosophy that focuses on identifying and addressing the most significant limiting factor that stands in the way of achieving a goal). The primary goal is to maximize the flow of deliverables based on resource capacity, materials, and other inputs while minimizing time and resource waste.

Why It Matters for the Exam

This concept appears frequently in PMI exam questions about adaptive and hybrid project management approaches, particularly in questions testing your understanding of Kanban, WIP limits, and flow optimization. You will encounter it in situational questions asking how to manage team capacity, improve delivery speed, and handle bottlenecks in flow-based environments.

Key Points to Remember (for the exam)

• WIP Limits: Flow-based projects use charts to limit the amount of work in progress. When a column approaches its WIP limit, project team members can "swarm" around the current work to help those working on tasks that are slowing the flow.

• Cycle Time vs. Lead Time: Cycle time is the time from when a task starts until it is completed. Lead time is the time from when a task is put on the board until it is delivered.

• Kanban Board Structure: Different color sticky notes can represent different types of work, and dots can show how many days a task has been in its current position. The order of items in the Ready column can be changed, making this unpredictable.

• Burn Charts: Burn charts (burnup or burndown) show project team velocity. Velocity measures the productivity rate at which deliverables are produced, validated, and accepted within a predefined interval. A burnup chart tracks the amount of work done compared to the expected work.

• Flow Optimization Goals: Maximize flow of deliverables based on resource capacity, materials, and other inputs. Minimize time and resource waste while maximizing efficiency of processes and throughput of deliverables.

• Key Concepts: Theory of constraints focuses on identifying and addressing the most significant limiting factor (constraint) that stands in the way of achieving a goal.

• Task Swapping: Tasks can be swapped with other tasks at any time on a Kanban board, providing flexibility in priority management.

Typical PMI Exam Example

A project team using a Kanban board notices that the "In Progress" column is approaching its WIP limit of 5 items. Two team members have completed their current tasks. According to PMBOK v8, what should the team do? Answer: Team members should "swarm" around the current work to help those working on tasks that are slowing the flow, preventing the column from exceeding its WIP limit.

PMI Exam Traps

• Trap: Confusing cycle time with lead time

• Reality: Cycle time starts when work begins; lead time starts when work is added to the board (includes waiting time)

• Trap: Thinking WIP limits are optional suggestions

• Reality: WIP limits are enforced constraints; when a column approaches its limit, the team must swarm to complete existing work before adding new items

• Trap: Confusing burnup charts with burndown charts

• Reality: Burnup charts show work done vs. expected work; burndown charts show remaining work over time

• Trap: Assuming Kanban boards have fixed priority order

• Reality: The order of items in the Ready column can be changed at any time, allowing flexible priority management

Important PMI Connections

Quick Review Questions

1. What is the primary goal of flow-based project management approaches according to PMBOK v8?

2. When a column on a Kanban board approaches its WIP limit, what action should project team members take?

3. What is the difference between cycle time and lead time in the context of a Kanban board?

4. What does velocity measure in flow-based projects, and which type of chart can show it?

5. What is the theory of constraints, and how does it relate to flow-based project management?

PMBOK v8 Reference

Section 5.6 - Flow-Based Projects and Kanban Boards (PMBOK v8, passages on Kanban method, WIP limits, cycle time, lead time, burn charts, and theory of constraints)