What is a construction schedule?
A construction schedule can be described as a timeline that construction managers adhere to throughout a building project to determine the order of construction activities.
By utilising construction schedules, managers can track dependencies, deliverables and milestones so that the entire project stays on schedule and within budget.
Types of construction schedules
A wide variety of construction schedules are available for selection. In a construction project, it is optional that an entire team uses a single format of the schedule and can adhere to multiple scheduling methods.
By understanding the main differences between standard scheduling techniques, you can select a method that is the most suitable for your construction project.
Some examples include:
• Critical Path Method (CPM): This type of schedule helps managers estimate the total completion time of a construction project by highlighting all dependent tasks within your timeline.
Since these tasks are presented successively, the team cannot proceed to the next task until the previous one is completed. By utilising this method, construction managers can appropriately anticipate changes to the completion date when there are delays or speedups in critical path activities.
• Program Evaluation and Review Technique (PERT): This type of schedule allows construction managers to estimate the completion date of a construction project by factoring in different pessimistic and optimistic considerations that are likely to impact the schedule forecast.
Here, managers are recommended to begin with a diagram of the building project, utilising the PERT formula to weigh time estimates and factor in different considerations. This method is preferred for those projects that are more sensitive to risk and highly beneficial to innovative or novel construction projects.
• Gantt Chart: This is the most commonly utilised method to project the estimated timeline. Managers are recommended to utilise a simple spreadsheet that lists each task that needs to be completed in the project and track their progress over time.
This document allows managers to update future activities and completion dates based on the actual progress of the project. This is the preferred method by many construction managers, as it allows for a high-level assessment of the overall progress. Additionally, it is quick, user-friendly, and interactive, making it easy to spot any potential problems or delays.
• Line Of Balance (LOB): The line of balance chart allows managers to track actual progress against anticipated progress. It is the best method for construction projects involving repeated units, such as multi-floor buildings or similar rooms.
As the task needs to be repeated on each floor, managers can calculate how long each repetition takes using this method. Using their observation, managers can predict the time needed to complete the remaining units. This method is also helpful for managers, as it allows them to adjust schedule forecasts if a team completes the repeated tasks faster.
• Quantitative scheduling: Quantitative scheduling is the method of utilising equipment and materials at different locations in the most efficient manner.
Another popular name for this method is the Q schedule. The focus of this technique is to find a method to allocate resources and organise activities so that it reduces the overall budget. This visual method displays the duration and quantity of the resources needed to complete a specific task at a specific location.
• Resource scheduling: This method allows you to prioritise the effective allocation of resources while simultaneously considering time factors, space constraints, funding issues, labour costs and other important project details. By utilising this method, you can deal with resource constraints in two ways: resource levelling and resource smoothening.
Resource levelling is allocating resources consistently but adjusting the project schedule. Similarly, resource smoothing prioritises time constraints and increases the consistency of resource allocation. So, if your crew does not work overtime but adds weeks to the project, it will be categorised as resource levelling, and if you make your crew work overtime, it is resource smoothening.
• Last planner system: This method helps you prepare a project schedule focusing on a short upcoming period. Generally, the focus is on six weeks or less. This type of planning is utilised as a part of the meet-ready phase, and construction managers utilise the look-ahead schedule to prepare for upcoming work. The process is further elaborated and incorporated into a weekly plan.
• Master schedule: This schedule compiles all high-level scheduling details of the construction project into one document. This comprehensive and user-friendly document helps managers identify individual work breakdowns, deliverables, milestones, structural elements and potential delays in one go.
The other name for this schedule is an integrated master, management or significant milestone schedule. The benefit of this schedule is that it also includes a Gantt chart to improve the visualisation for managers.
• Milestone chart: This schedule helps to summarise the significant milestones of a construction project into a simple, uncomplicated and easy-to-read chart.
Examples of milestones include important dates, deliverables and key events. The focus is on milestones rather than tasks or activities, making the schedule more holistic. Other typical milestones include contract award, permit approval and final walk-through.
• Schedule baseline: This schedule provides a targeted timeline for construction so that managers can finalise and obtain approvals for the project schedule from the beginning. If they’re able to obtain approvals at inception, managers can have a basis for comparison. This makes it helpful to track the actual progress and determine if the activities are currently behind schedule.
What makes a good construction schedule?
Understanding the high-level process of drafting a construction schedule can aid you in your next project. The following are the five main steps to creating any successful construction schedule:
1. Gather project information: To develop an accurate construction schedule, begin by understanding every aspect of the project.
Therefore, you need to review the budget, specification plans, list of subs contractors, building codes, regulations on zoning, bill of materials and procurement plans; after understanding what is coming from where create a Work Breakdown Structure (WBS) that will allow you to stay organised as you complete this process.
2. Select a project management tool: A wide variety of construction-specific applications and software are available for managers to choose from. Utilising such applications make scheduling easier and visualisation simpler.
If you want to avoid investing in intuitive project management tools, Google sheets or Excel provides an excellent alternative. Select any tool that the other project participants are already familiar with to enhance communication across construction stakeholders. The project management tool that you ultimately select should have viable communication features, readily available templates and good scheduling functionality.
3. Create a draft schedule: When you are in the process of drafting the initial schedule, make sure to consider task dependencies and provide a buffer. This buffer or extra time will help you account for unexpected delays. Adding buffers to areas that are commonly “sticky,” such as code inspections, may protect the pace of your work. Adding buffers makes your completion estimate more realistic, and your clients or stakeholders are not overwhelmed.
4. Refine the basic construction schedule: To confirm the viability of the schedule, share the draft with every relevant stakeholder. All communications should be recorded for later reference and the list of procurement should also be added. Utilising WBS and Gantt charts makes visualisation easier.
Once the draft is finalised and approved by everyone, it becomes the final project schedule. The best method to determine buffers is to review past projects with similar specifications to get an estimate of how much time it takes to complete specific tasks. Buffers depend significantly upon the type of project and local conditions; therefore, reviewing past projects is extremely helpful.
5. Maintain open lines of communication: Your schedule and Gantt chart will continue to develop as your construction project progresses. The involvement should be natural and holistic. To keep everything on track, remember to update the schedule regularly. Even when delays occur, remember to update them, so that the communication lines are always open.
Additionally, you can reduce the impact of the delay by re-locating resources or making adjustments in other phases of the schedule. It is also recommended to hold regular meetings with the project participants before you decide upon the communication channels.
This is because some people prefer to avoid emails, whereas others prefer telephonic conversations. Getting everyone on the same page is helpful as it keeps the communication process smooth and obstacle-free. Additionally, when the communication channel is agreed upon, updates can be sent via that communication channel so that everyone is aware of the project’s current progress.