Construction scheduling has long been considered an art. Project managers have honed the ability to set a complex set of tasks in line to come off without a hitch.
But what if there is a hitch? Supply delays, worker shortage, or weather constraints could bungle up the most carefully considered project schedule, and getting it back on track is essential to limit losses. The almost endless set of variables that go into any construction project can be overwhelming for even the most seasoned construction veteran.
Construction project scheduling methods
To try to cope with all the variables, there are a number of different methods to scheduling projects, and each focuses on a specific variable. So what is the best way to schedule construction projects to make the most of all the resources on the project and keep everyone working efficiently?
The following are some of the most common project scheduling methods.
Critical Path Method
Critical path is taught to construction managers as a basic way to understand how all the bits of the work come together. It uses a diagram to demonstrate the interdependence between elements of a project, with the critical path tasks representing the activities required to finish the construction project.
Critical path activities must be completed on time or else the entire construction project will be delayed, so this method helps establish key deliverables and their deadlines. The longest sequence from the beginning to the end of the project establishes the length of time it will take to finish a project.
The critical path method used to be done entirely manually, but with the size and complexity of modern projects there can be thousands of activities to plot out. Project management software can now establish the path quickly and recalculate when changes in the project occur.
On its own, the critical path method doesn’t consider resource allocation, so other methods may need to be combined with it to complete a total project breakdown.
Program Evaluation and Review Technique (PERT)
Like critical path, the program evaluation and review technique uses a diagram as a visual tool to understand elements of the project, and the order in which they must occur. Whereas critical path focuses on activities required to finish a project, PERT instead focuses on the milestones or events that need completion and the time it will take to do them.
PERT was designed to handle activities with uncertain timelines, so it allows for three different time estimates: optimistic, most likely, and pessimistic. Because they handle things so differently, PERT is often used in conjunction with the critical path method.
Line of Balance
The Line of Balance method forms the basis of its organization using blocks of activity that are often performed together by a skilled workforce, and will be repeated multiple times throughout a project.
Project managers can line up the blocks so that one team can take over for the next block as soon as the team that comes before it is done. Done correctly this method is quite efficient because each project team has a continuous flow of work and there only needs to be one team with each skill set on the job site.
Another benefit of this method is that it can identify exactly where a project has a tendency to go off schedule or cost plans.
The Q Scheduling technique allows contractors to see the relation between how a job is done and how much materials it requires and how much it costs to do it. In this way it helps project managers to order materials when they’re needed rather than storing them unnecessarily.
Resource Oriented Scheduling
In times of tight resources, the Resource oriented scheduling system may come in particularly handy. It schedules tasks based on when the necessary components like space, labor, and raw materials, will be available to do them.
Last Planner System
Closely related to the lean construction phenomenon, the Last Planner System was created to produce a predictable workflow by bringing in the people who are responsible for doing the work to collaborate on the project plan.
A Gantt Chart is a bar chart that shows a visual representation of tasks scheduled over time. The vertical axis lists tasks that need to be done, while the horizontal axis represents time. It reveals overlapping and related projects, and demonstrates how long each task takes. A key benefit of the Gantt chart is that it clearly shows the work that needs to be done on specific days.
How will you schedule projects?
Each of these methods has strengths and weaknesses in construction planning, and in truth they often need to be used together for maximum effect. In large, complex projects it can be easy to make mistakes on project time estimates, to miss dependencies, or to disregard resource availability when creating a project timeline. There are just a lot of balls in the air.
And scheduling is critical. Right from the moment of the first bid, a project schedule can reflect a contractor’s level of professionalism, impact the final expected costs, and determine how smoothly a project goes.
Software solutions can take the guesswork out of project scheduling. They also allow contractors to track metrics and adapt the project to last-minute changes.
Project scheduling solutions
These solutions come in many different forms, and each is unique in the way it operates. Whittle down your choices by shopping for construction project scheduling software with some key criteria in mind.
At the very least, your chosen solution should be easily usable (not just for the techy crowd) and offer secure data storage. It should also work with your chosen method of project scheduling so it fits your projects and company credo.
ALICE is a solution that doesn’t just stick to one method. Instead, it understands construction by "encoding" the means and methods into a language that its algorithm can interpret, to simulate and explore all the scheduling options that satisfy a project's constraints. No more following your gut.
By using its built-in simulator and optimizer, ALICE helps construction teams generate project schedules that reduce duration by an average of 17%, reduces labor costs by 14%, and equipment costs by 12%. And if things change along the way, your schedule does too: ALICE is parametric, so any changes you make in terms of labor, equipment or material, will propagate throughout the project.
Get it right, keep it flexible
It is so common for a construction project schedule to get off-track, since there are so many factors and dependencies that tie the whole picture together. Using a parametric solution such as ALICE can help professionals in the construction industry mitigate those delays and optimize their resource mix to expedite project progress and deliver their project more efficiently.