Calendars help organize work and resources in project management. Two key commonly used calendars are the project calendar and the resource calendar. These calendars are vital in scheduling and are developed during the project’s planning phase.
While these calendars are updated throughout the project, updates are less frequent than those in other documents, such as the stakeholder register or risk register.
The project calendar outlines the working days and times available for project activities, while the resource calendar focuses on specific team members or equipment availability. Both calendars are visual, offering a quick and clear overview of schedules.
In this article, I will explain the project calendar vs resource calendar.
What is a Project Calendar?
A project calendar is an essential tool in project management. It shows the working days, shifts, and times available for project activities. This calendar helps you plan and organize tasks effectively, making it a key input for developing the project schedule.
You can use multiple project calendars to accommodate different work periods. These calendars are flexible and can be updated as needed. For instance, you may need to adjust them when new public holidays are announced, or existing ones are canceled.
Project calendars are especially useful in emergencies. They highlight non-working days, enabling you to plan urgent tasks or shifts to address crises. They also support scheduling overtime and compressing timelines when necessary.
Key Points:
- It displays available working days, shifts, and times.
- It helps optimize and compress schedules.
- Multiple project calendars can be used in a single schedule.
The PMBOK Guide considers the project calendar part of the organization’s process assets. By providing clear and structured timeframes, it ensures smooth planning and execution.
What is a Resource Calendar?
A resource calendar helps you determine when and for how long specific resources, such as people, equipment, or consumable materials, are available for your project.
The resource calendar is invaluable if your project is part of a larger program or portfolio with shared resources. It allows you to check the availability of shared resources and plan their usage effectively. This information is critical for developing the project schedule and ensuring smooth workflows.
Resource calendars can include additional details about resources, such as their skills, educational qualifications, or the type of equipment available. These attributes make it easier to assign tasks to the most suitable resources.
Key Points:
- They display the availability of resources.
- They are particularly useful when resources are shared among projects.
- They cover various resource types, including human resources, equipment, and consumables.
Resource calendars are the staff management plan. By providing clear insights into resource availability, resource calendars help you manage resources efficiently and avoid conflicts or delays.
Project Calendar Vs Resource Calendar
Due to their similar names, many professionals assume that project calendars and resource calendars serve the same purpose or can be used interchangeably. However, this is not the case. These calendars are distinct and serve different functions, making them incomparable.
A project calendar specifies when project work can or cannot take place, such as working days, holidays, and shifts. In contrast, a resource calendar focuses on the availability of specific resources, like team members or equipment, for the project.
Resource calendars are more dynamic and often updated frequently to reflect changes in resource availability. On the other hand, project calendars usually contain fixed information, such as weekends or holidays, and are updated less often.
These calendars are designed to complement each other, not to compete. Together, they ensure efficient scheduling and resource management throughout the project lifecycle.
The following table shows the key differences between the project and resource calendar:
| Parameter | Project Calendar | Resource Calendar |
| Purpose | Shows working days, shifts, and times for project activities. | Employee schedules and equipment usage times. |
| Scope | Focuses on general work periods for the entire project. | Focuses on individual or shared resource availability. |
| Contents | Includes workdays, holidays, and shifts. | Includes resource availability, skills, and qualifications. |
| Flexibility | Can use multiple calendars for different work periods. | Tracks shared or dedicated resources for multiple projects. |
| Examples | Public holidays, planned work shifts. | Employee schedules, and equipment usage times. |
A Real-World Example of the Project Calendar and Resource Calendar
Suppose you plan to paint your six-room house next month. You want to complete the project in 14 days (two weeks), so you decide to create a project calendar to organize your schedule.
Since you attend college from 8:00 AM to 2:00 PM on weekdays, this time will be marked as non-working hours. You plan to work from 4:00 PM to 7:00 PM on weekdays. Saturdays and Sundays are your free days, so you schedule work from 9:00 AM to 4:00 PM on weekends.
You plan to attend a wedding during the second week, marking Tuesday and Wednesday as non-working days.
Your project calendar now includes:
- Working Hours: 4:00 PM to 7:00 PM on weekdays and 9:00 AM to 4:00 PM on weekends.
- Non-working Days: Tuesday and Wednesday in the second week.
Next, you create a resource calendar. After two days of cleaning, you start painting on the third day. For the ceiling, you borrow a ladder from your neighbor, available for three days (days 3–5). On days 13 and 14, your brother is free and has offered to help. You include this information in your resource calendar.
With both calendars ready, you are set to manage your project effectively.
Benefits of Using Project Calendars and Resource Calendars
Project calendars and resource calendars are essential tools in project management. Their benefits include:
- Facilitating Schedule Development: These calendars help you plan and organize work by clearly showing working days, non-working days, and resource availability, making it easier to create an accurate project schedule.
- Supporting Schedule Compression: When deadlines are tight, these calendars are instrumental in identifying opportunities for overtime or additional shifts to compress the project schedule.
- Enhancing Resource Management: By ensuring the smooth allocation of resources, these calendars help avoid conflicts and ensure tasks are assigned efficiently.
- Simplifying Estimation: They provide a clear overview of available time and resources, making it easier to accurately estimate task durations and resource needs.
- Improving Communication and Efficiency: These calendars promote better communication among team members and enhance overall efficiency by providing a visual representation of schedules and resource usage.
- Preventing Employee Overload: Resource calendars help balance workloads, ensuring employees are not overburdened and reducing the risk of burnout.
Project calendars and resource calendars ensure better planning, efficient resource usage, and smoother project execution.
Precautions with Project and Resource Calendars
The project environment is constantly changing. Team members may join or leave, impacting the resource calendar. Similarly, unforeseen events, such as a newly announced holiday, can disrupt planned workdays and affect the project calendar.
In such cases, updating the project and resource calendars to reflect these changes is essential. Failing to do so can render the calendars ineffective, leading to scheduling conflicts and resource allocation issues.
You may also encounter the term “task calendar.” A task calendar is a variation of the project calendar in which specific tasks are added to the schedule. When resource availability is applied, it effectively functions as a resource calendar. However, since the PMBOK Guide does not explicitly mention task calendars, we will not delve into their details here.
Keeping project and resource calendars accurate and up-to-date ensures smooth operations and avoids unnecessary conflicts.
Summary
The project calendar and resource calendar are key tools in project management. While the project calendar focuses on working days, shifts, and times, the resource calendar tracks resources like people and equipment availability. Keeping these calendars up-to-date is crucial for smooth project execution. Update them to avoid resource conflicts with other projects and delays in project completion.
By managing both calendars, you can ensure better scheduling, efficient resource allocation, and a higher likelihood of project success. Together, they form the backbone of organized and conflict-free project management.