2023-04-24
I have a love-hate relationship with schedules.
I genuinely appreciate the what a schedule can reveal about a project and I know that a well-crafted schedule can contribute to the efficient completion of a project.
I also find the modern approach to scheduling to be lacking. Outside of the construction industry, traditional schedules have been all but abandoned completely because they often cause more problems than they solve.
But, in the ever-evolving world of project management, traditional scheduling methods remain popular for their ability to provide a structured approach to managing tasks and deadlines, despite their limitations.
And, it’s crucial for project managers to understand when and how to use them effectively.
A Quick Overview of Scheduling Methods
I’ve worked on projects from $10k to $1B and while the options for software are limitless, they all approximate the same traditional scheduling methods: Gantt charts and the Critical Path Method (CPM)
These methods provide project managers with valuable tools for planning and tracking project progress. These methods allow project managers to visualize the sequence of tasks, identify the critical path, and estimate project completion dates.
Gantt Charts
A Gantt chart is a bar chart that represents project tasks along a timeline. Each task is represented by a horizontal bar, with the length of the bar indicating the duration of the task. Gantt charts help project managers identify dependencies between tasks, allocate resources effectively, and monitor project progress.
Critical Path Method (CPM)
CPM is a technique used to determine the longest sequence of tasks that must be completed on time for a project to finish on schedule. By identifying the critical path, project managers can prioritize tasks, allocate resources, and manage risks associated with potential delays.
CPM and Gantt charts are used in conjunction to get a high-level view of the project. But how high-level is too high-level? And how much detail is too much detail?
The Limitations of Traditional Methods
Despite their usefulness, traditional scheduling methods can be misused or over-relied upon, leading to inefficiencies and potential project delays.
Failure to Distinguish Between Hard and Soft Logic
Hard logic refers to the mandatory dependencies between tasks, while soft logic represents preferential relationships based on best practices or experience.
Most scheduling methods (including all that I’ve seen) treat all logic the same.
But they’re not the same, are they?
If you had to make a decision on how to adjust a schedule when faced with a project change or delay, which activities offer more opportunities for crashing and fast-tracking?
(Spoiler: its soft logic)
Not being able to distinguish visually between hard and soft logic makes schedule management more difficult. Scheduling software being unable to distinguish between hard and soft logic reduces the ability for optimization.
Introducing Human Error
Traditional scheduling methods often rely on manual input and manipulation, increasing the potential for human error.
Mistakes in data entry, calculations, or task sequencing can lead to incorrect schedules and misguided decision-making.
But beyond that, the point of traditional scheduling methods and related software is to automatically calculate the shortest possible path and identify next steps.
What if the longest path includes soft logic that the scheduler designed into the schedule? This isn’t necessarily human error but if your goal is to complete a project as quickly as possible, then it certainly is.
Because soft logic can be reworked, it often is reworked. If you’ve programmed your project sequence using soft logic, or you’ve got a lot of trade logic (soft logic determined by resources), most of your time will be spent breaking and rebuilding logic.
From Experience
I started my career working on wind farms. I’ve brought this up before, I’m sure.
Just in case you’re not familiar, a wind farm involves building anywhere from a couple to a couple hundred nearly identical wind turbines.
Each turbine required one excavation, one foundation, 3-4 tower components, a nacelle, and three-blades.
I had to manually connect all similar activities for each wind turbine, leading to a complex and time-consuming scheduling process.
The project I was on had 49 turbines. If I didn’t connect the foundation items, the schedule would show them all happening at the same time, as early as possible.
So all 49 excavations were connected in sequence, all 49 rebar installation, all 49 concrete formwork activity, all 49 concrete pours, etc.
During the project we had an issue with a concrete pour on turbine #14, causing the whole turbine delivery to be delayed. The schedule, as it was built, insisted that no other turbines could be completed until T14 was completed. But of course that was ridiculous.
We could move T14 later in the project but that meant breaking all the logic connecting T13 to T14 and T14 to T15, then connect T13 to T15.
If I was lucky, T14 would be moved to the end of the project. But I was not lucky. I had to break the logic between two later turbines, then connect them both to T14.
Its not intensive work, nor is it particularly difficult. But it is time-consuming and annoying.
T14 was not the only turbine we had to resequence throughout the project.
The Benefits of Short-term Lookahead Schedules
The more detail you add to a schedule, the more difficult and time consuming it becomes to resequence. For this reason, if you have to use a traditional scheduling software, you’ll likely want to have it show only major scopes of work.
But then how do you actually manage the finer details? If you read the heading of this section, it should be obvious:
Short-term Lookahead Schedules.
A short-term lookahead schedule is exactly what it sounds like. A two-to-three week schedule that includes only the activities you plan to complete in the next few weeks.
This schedule can show more finite breakdowns with specific plans and details.
I look at this way: when you’re planning a road trip, you’ll plan the outline of the trip using Google Maps, but your minute-to-minute driving decisions are made based on current traffic conditions and what you can see in the moment. If you need to make a change based on current road conditions, your map should update to accomodate.
Use your schedule to plan the general outline of your project and to identify any key dependencies that may hold up your project.
Build your short-term lookahead schedule based on the major activities called out in your primary schedule.
Use the lookahead to plan organize your crews, and coordinate on the day-to-day.
Alternative Software Solutions for Managing Soft Logic
To further enhance the project scheduling process, project managers can explore alternative software solutions that incorporate soft logic more effectively.
We’re currently in the process of developing a software that will treat soft logic as inherently different than hard logic.
With hard logic, there is a mandatory order to activities that cannot be violated. With soft logic, you’re usually governed by space or crew availability.
The goal would be a software that uses a “not while” condition for soft logic, allowing the software to decide the sequencing of tasks based on the constraints and preferences defined by the project manager, but would update automatically.
For example:
You’re a scheduler in charge of a project to paint each floor of a 5-storey building. There’s no reason you couldn’t paint them in any order, but you can’t paint them all at once because you only have 1 crew.
Rather than assign hard logic dependencies to all the activities, you assign a not-while condition to all five floors. If an issue arises with a predecessor to floor 2 and you can’t proceed, the schedule would automatically bump floor 3 up, as it would be the next available activity.
While this approach could also be handled using resource leveling, resource leveling does not handle sub-contractor conflicts well. I.e. I may want to install the windows or the carpets, but not at the same time. They can be happening in different rooms at once, but not in the same room.
Best Practices for Project Managers
To optimize scheduling methods and improve project outcomes, project managers should consider the following best practices:
Accept the Value and Limitations of Traditional Scheduling Methods
Recognize the strengths and weaknesses of traditional scheduling techniques and use them appropriately. Understand when to rely on Gantt charts and CPM for high-level planning and when to utilize short-term lookahead schedules for more detailed planning and adjustments.
Both Gantt Charts and the CPM method are great for outlining hard dependencies that will determine the minimum duration of the project.
Gantt Charts are an excellent tool for tracking completed progress on a project.
Avoid Adding Too mUCh Detail (until Needed)
While it is essential to have a well-planned schedule, spending excessive time on refining a schedule may yield diminishing returns.
Project managers should strike a balance between creating a thorough schedule and allocating time to other crucial project management activities.
Gantt Charts are not agile enough to effectively manage thousands of short-term activities. So keep your activities general.
For example: If you need to pour a concrete foundation, you’ll need to form the foundation, install reinforcing steel, pour the concrete, wait for it to cure, and then strip the forms. This level of detail may be too fine for a Gantt chart as you’ll find yourself breaking and rebuilding dozens of dependencies if you need to resequence the project.
Instead, add a single activity for “form-reinforce-pour concrete foundation” and set the duration to the expected combined duration.
You can manage the finer details on your short-term lookahead schedule.
Don’t Ignore Schedules Altogether
Despite the potential limitations and drawbacks of traditional scheduling methods, they still provide valuable insights and structure for project management.
Too many times I’ve seen schedules get so cumbersome and out of step with the reality of the project that project managers and superintendents:
- Refer to the schedule only occasionally,
- Ignore the schedule and plan their own work, and
- Stop updating the schedule altogether
Ignoring schedules altogether can lead to disorganization, miscommunication, and project delays.
As stated above, the main benefit of a large schedule is the ability to see how activities completed today affect the final completion of the project.
For a small project, it may be possible to have a general idea of which activities need to be done first, or you may only have one crew so everything will be done in sequence.
But for large projects, its difficult or impossible to intuit the consequences of your early decisions.
So its important to focus on using the most appropriate scheduling tools and techniques for each project phase and continuously update and adjust the schedule as needed.
Final Thoughts
Traditional scheduling methods, such as Gantt charts and CPM, have served project managers well for many years. While these techniques provide valuable structure and visibility into project progress, they also have inherent limitations that can lead to inefficiencies and errors.
By incorporating short-term lookahead schedules, leveraging advanced software features to manage soft logic, and adhering to a pragmatic approach, project managers can improve their scheduling methods and ultimately increase project success rates.
BG
