To calculate Slack Time (ST), subtract the Early Start Time (EST) of an activity from its Late Start Time (LST).
The Slack Time Calculator determines the amount of leeway or flexibility available in scheduling tasks within a project without delaying its overall completion. It is particularly useful in Critical Path Method (CPM) and PERT (Program Evaluation Review Technique) analyses.
Formula
ST = LST − EST
| Variable | Definition |
|---|---|
| ST | Slack Time (amount of flexibility in scheduling) |
| LST | Latest Start Time (latest possible start time) |
| EST | Earliest Start Time (earliest possible start time) |
Solved Calculations
Example 1
An activity has an LST of 10 and an EST of 8.
| Variable | Value |
|---|---|
| Latest Start Time (LST) | 10 |
| Earliest Start Time (EST) | 8 |
| Slack Time (ST) | 2 |
Example 2
An activity’s LST is 15, and its EST is 12.
| Variable | Value |
|---|---|
| Latest Start Time (LST) | 15 |
| Earliest Start Time (EST) | 12 |
| Slack Time (ST) | 3 |
What is Slack Time Calculator?
The Slack Time Calculator is a valuable tool used in project management and scheduling to determine the amount of time an activity can be delayed without impacting the project’s overall completion date.
It simplifies the calculation of slack time, ensuring efficient planning and resource allocation in critical path analysis (CPA).
Slack time, also referred to as float, is essential for identifying flexible tasks and ensuring project timelines remain unaffected.
For example, by inputting parameters like earliest start time, latest start time, and duration, the calculator quickly evaluates whether tasks are on the critical path or have some flexibility.
In that way, this calculator seamlessly helps project managers optimize schedules and prioritize tasks effectively.
Whether you’re calculating slack time in PERT (Program Evaluation and Review Technique) or CPM (Critical Path Method), this tool is indispensable for managing project timelines and reducing delays.
Final Words:
In summary, the Slack Time Calculator is a practical resource for project managers seeking to streamline schedules and maintain efficiency. By accurately identifying task flexibility, it empowers better decision-making and improved project outcomes.
