Understanding what method or framework will work for your team can also be done by looking at the techniques for addressing project constraints. To start digging deep into the constraints, let’s discuss the project management triangle AKA ‘The Iron Triangle’. If you ever managed a project, you’re likely to work with the iron triangle, even if you haven’t acknowledged it in such an official capacity.

The iron triangle models the constraints project managers work with on every project they oversee. It also helps to explain how the different project management methods align. The aspects it addresses are:

  1. Scope - the technical work to be done.
  2. Schedule - the total calendar time to execute the work.
  3. Budget - the total amount of money will cost for the project.

All the aspects of the Iron Triangle are constraints and costs to the organization.

  • More schedule means a delay of project benefits and tie-up of capital.
  • More budget means more money or capital invested.
  • More scope means larger products to support or maintain for the organization.

These are all forms of cost and constrain how the work can be accomplished when they are fixed.

Let’s focus on how different PM methodology handles these costs and constraints. This article will only address the very common types of project management methods - Agile, Traditional/Waterfall, and Lean.

  • Agile - varies scope against fixed budget and schedule.
  • Traditional - varies budget against fixed scope and schedule.
  • Lean - varies schedule (or solution time) against fixed scope and budget.

The goals and requirements of each method are essential for understanding the place of each method in the project manager’s arsenal:

  • Agile: The goal is speed (deliver early versions fast), and requires trust to minimize scope for fast value delivery.
  • Traditional: Goal is efficiency (best price), and requires efficiency to deliver the lowest cost on time and budget.
  • Lean: The goal is to innovate (solve problems), and requires expertise to minimize the time of delivery.

Each method has its goals, but it also has its paradigms of managing against the goal. The result can be very different and similar means of managing each element:

Controlling Scope


1. Work Breakdown Structure (WBS) - controls work by concretely defining its components.

  • It often has three levels: Product, Major Features, Feature Components.
  • Used to define what will and will not be in a project.

2. Change Control Board (CCB) - controls changes to the WBS by committee review.

  • Includes all major stakeholders.
  • Must be organized and often slows changes to a project.


1. Tickets - identify work items and their priority for a response (urgency and impact).

2. Requests - these are informal or semi-formal requests that could be ticketed.

3. Notes

  • Both tickets and requests go into a queue for work and are executed through a value stream.
  • Value streams are steps to complete work (e.g. define, analyze, build, test).


1. Product Backlogs - the list of work to be done for the entire project. It’s an ordered list of work increments.

2. Sprint Backlog - the work that will get done during the sprint.

Note that Backlogs are used for Tickets in Lean and Stories in Agile. You can also have what’s often called the “Kanban Sandwich” where Lean processes are used to set Sprint Goals, Agile is used to manage a Product and Sprint Backlog, and then work during a sprint is managed in a Lean process.

Controlling Schedule


1. Estimated Tasks and Schedules - work is estimated and modeled for precedence.

2. Program Evaluation and Review Technique (PERT) - adds stochastic modeling of task completion.

3. Critical Path Method (CPM) - uses deterministic modeling to identify critical tasks for on-time delivery.

4. Notes

  • Determining the critical series of tasks helps to focus managers in traditional on the important tasks.
  • This does not necessarily align with business importance.
  • Schedule and scope are fixed, however, scope modeling comes before scheduling to define estimates and dependencies in the work.
  • A schedule is considered the primary tool in Traditional Management for controlling delivery.


1. Kanban & Queues - work is managed in a list and executed based on priority.

2. Service Agreements - sets the priority of work by defining what is critical, major, or minor.

3. Notes

  • The Kanban & Queue techniques, along with the Service Agreements, allow for Lean projects to adjust when delivery will occur for each work item.
  • This is intended since the schedule is varied in Lean projects.


1. Timeboxes - a set period of time in which the most important work is done first.

2. Releases and Roadmaps - it sets goals for major features to be released together.

3. Notes

  • Timeboxes are used at all levels of the project to set deadlines.

- Sprints are given a fixed time to drive improvement.

- Any work not done in the timebox goes back into the backlogs.

  • Releases and Roadmaps set objects for multiple sprints that can be met at varying quality levels.
  • This allows for the most important work to achieve an objective to get done first.
  • This aligns the business’s importance with what work actually gets done on time.

Controlling Budget


1. Earned Value Management (EVM) - compares current performance to the plan.

  • Planned Value (PV) - shows the cost over time expected to complete the work on schedule.
  • Earned Value (EV) - shows how much work is completed to date.
  • Actual Cost (AC) - shows the cost so far to complete the work.

2. Cost Centers

  • Evaluates the differences in performance by cost center.
  • Cost Performance Index (CPI) is the factor EV / AC, were above 1.0 means good performance.
  • Schedule Performance Index (SPI) is the factor (EV / PV), where above 1.0 means good performance.
  • This allows you to estimate the costs or savings expected for on-time delivery of the total scope.


1. Service and Severity Levels - sets the level at which the company reaps benefits from the solutions.

  • Service Levels set the Goal.
  • Severity Levels set the Impact of meeting or not meeting the goal for different problem types.

2. Key Performance Indicators (KPIs) - evaluate performance against goals for set time periods.

  • If the KPI is meeting or exceeding the Service Level Goal, then you’re making money.
  • KPIs will often vary over time, so it’s important to look at the trend.


1. Return on Investment (ROI) - the net income as a ratio to total investment.

  • Positive ROIs should be expected after the first or second release of a product.
  • Allows for selecting and refining the backlogs.

2. Burndown Charts - shows progress in achieving the backlog over time.

  • Used for projects that haven’t yet been released, or projects that cannot easily estimate ROI.
  • Projects often start with a set of stories and estimated story points.
  • The expectation is a linear burndown - meaning a linear decrease in the total remaining work to be done.
  • Teams often are slow at the beginning and speed up over time, or hit snags that stall backlog burn.