Project delivery plan optimisation metrics

Critical Path Drag and Activity Spread

FEATURED PAPER

By Alex Lyaschenko, PMP, MMath

Sydney, Australia

Abstract

The Critical Path Method is used to identify the sequence of tasks that are critical to completing a project on time. Schedule optimisation is an essential step in schedule development and maintenance processes. Project teams need metrics that support them to optimise project delivery plans effectively. Critical Path Drag is one such metric that is not well-known yet. While this metric is very useful for Project Delivery Plan Optimisation, the lack of practical implementation in project delivery systems slowed down its rollout. This paper explains how this metric works, including information not previously explained in the application of the metric in complex delivery model scenarios. Additionally, a new ‘Activity spreading’ concept and Critical Path Metrics (‘Elapsed Drag’, ‘Drag Lag’, and ‘Activity Spread’) are offered to extend the family of schedule optimisation metrics.

Project Delivery Plan Optimisation

The majority of project managers are familiar with the Critical Path Method (CPM) and apply it to manage their projects. Many scheduling software packages can compute and visualise Critical Path, making it easy to apply. Usually, a project manager accepts the calculation as the schedule. The CPM doesn’t consider resources, material and financial supply constraints. So, the next steps become to assign resources, baseline the schedule and start to manage project progress. The reality is that the first calculated schedule is only the tentative plan, giving just the data to implement the method fully. Once the initial CPM schedule has been computed and a logic diagram produced, the project manager can commence the next stage of the schedule development: final optimisation. If, for instance, project managers want to shorten the project duration, they now know where to start: the current critical path!

There are different ways of trying to shorten the project. Popular approaches are:

1. Shorten the duration of an activity on the critical path by:

• adding extra resources
• assigning resources with better productivity rates
• asking resources to work extra hours
• reorganise work by adding an extra shift(s)

2. Change logic by:

• performing consecutive activities in parallel
• overlapping critical path activities

3. Change logic or activity duration by

• changing the delivery approach (ex. workers with spades instead of a bulldozer)
• pruning scope (descope ‘nice to have’ features)

Less-known approach discussed in this paper include:

4. Start critical activities earlier by:

• increasing the duration of a critical activity allowing other critical activities to commence earlier

To be able to apply optimisation changes, the following questions need to be answered:

• Where should we add/remove these resources?
• Where should we change logic?
• Where should we review the scope?
• Where should we change assignment calendars?
• What will be the effect of such actions on the schedule and cost?

For the answers, we need Critical Path Method metrics.

More…

To read entire paper, click here

How to cite this work: Lyaschenko, A. (2024). Project delivery plan optimisation metrics: Critical Path Drag and Activity Spread, PM World Journal, Vol. XIII, Issue X, October/November. Available online at https://pmworldlibrary.net/wp-content/uploads/2024/11/pmwj146-OctNov2024-Lyaschenko-Project-Delivery-Plan-Optimisation-Metrics.pdf

About the Author

Alex Lyaschenko

Sydney, Australia

 Alex Lyaschenko is a planning and delivery consultant with over 25 years of experience in project portfolio management across different industries and countries. He holds a Master’s degree in Mathematics from Odesa Mechnikov National University and began his career in the technology sector and was in the origins of project management in Ukraine. He worked at Ukraine’s first project management consulting firm, where he helped establish project delivery offices across different industries and trained future project consultants.

After relocating to Australia, Alex contributed to multiple portfolio and program offices, supporting organisations in defining their vision, enhancing project delivery practices, developing standards, implementing PPM tools, and upskilling teams. Passionate about merging data with actionable strategies, Alex continues to shape the project management field by delivering insightful presentations and practical solutions that empower organisations to make data-driven decisions.

As a speaker, Alex has presented at numerous project management conferences, and his articles have been featured in leading industry publications.

Alex can be contacted at alex.lyaschenko@saluteenterprises.com.au