Project management is all about staying on the critical path and securing an early finish date. Hence, any project schedule is full of competing activity durations. Then, once an external factor results in a late start for an activity, it can lead to a late finish as well.
To stay prepared for all outcomes, project managers use the forward pass technique. This shows the earliest possible start date for an activity on the network diagram. In other words, it represents the fastest possible completion time for a given part of the project.
Utilizing this method can allow you to stay on the critical path. Focusing on a task where you can assign an early start, and early finish date is a smart move. Once you cross several items off the list that way, the project’s duration will shrink as a result.
Here are the benefits of the forward pass in project management:
- Enforce the critical path method at all times
- Learn from past experiences and apply new knowledge to great effect
- Predict the latest day for completing a task
- Keep an eye on any dependency task to craft an optimal action plan
Next, depict the project schedule in a graph. This will highlight all start/finish dates as per the plan. The following paragraphs will cover the basic terminology for project management.
The Project Stages
In short, a project comprises chains of activities. To summarize the completion date of the project, the project manager sets deadlines for a given task. Next, the project team notes which activity requires the completion of the preceding activity.
Estimate the Completion Date
Calculation methods show the project’s duration in time units. Such business periods are the key to a practical project schedule. This estimation applies to all types of tasks.
Some tasks cannot begin before the previous task is complete. Hence, successor activities rely on the good outcome of a key individual activity. Also, a predecessor activity can have many successor tasks.
Therefore, identify which tasks depend on the completion of some other task. This will allow you to sort them in chronological order. Next, insert the usual activity duration for the prior task and the possible latest date in the schedule. You can use project management software for this purpose.
Before the team can tackle a successor task, the previous task must fully finish. Various technical and organizational factors affect this workflow.
Aim for a Head Start
To discover which task can begin earlier than estimated, consider the overall completion rate. Usually, you can assign most of the predecessor activities an early start date.
For best results, convert such work milestones into calendar days. This will show the relations between tasks more clearly.
Earliest Finish Dates
Besides certain schedule constraints, some tasks can finish before the projected end date. Hence, that is their early finish date value.
In an ongoing workflow, the plan can change regarding those opportunities.
Example of a Common Workflow
- The first activity can start one day earlier. So, its early start date is the first day (ES=1). As for duration, it will last for two days. Hence, its early finish date is the second day of the project (EF=2).
- The second-in-line task begins on the third day and continues for five more. Thus, its dates stand as ES=3 and EF=7.
- The third date is also the starting point for the third activity. However, that one lasts for eight days. That means ES=3, while EF=10.
- The second task (EF=8) is a predecessor activity for the fourth task that should start on the eighth day. That task lasts for two days, so its values read EF=8; EF=9.
- The fifth activity lasts for five days but is a dependency task on both the third and fourth activities. As such, its start date cannot arrive before both of them are complete. So, the earliest date it can start is after the tenth working day since the third task reads EF=10. Hence, the final activity has these values: ES=11 and EF=16.
Make Up for Any Lost Time
To cover all fronts, note the latest possible date you can start an activity without severe issues. If all goes well, even that last resort will not cause you to miss the final deadline.
Thus, forward pass in project management is a great tool for keeping everything in check.
Set a Late Finish Date
This refers to the latest date you can finish an activity without upsetting the initial plan. So, the late finish date for all tasks will be the same as the project’s end date.
Here’s how to calculate those values for a given project task:
- Its late start date = the late finish date minus the activity duration plus a value of 1
- Its late finish date = the last start date of the successor task minus a value of one
In that way, you’ll use the forward and backward pass to hone in on the project completion date.
Note the Total Float Time
This is the detraction from a task’s possible early and late start dates. In other words, it’s the amount of leeway you have before you start losing time.
Calculate the Free Float Values
Some predecessor activities can drag on for a bit without delaying the later task’s start date. This is the free float time that you can use to ensure the follow-up tasks finish on time.
Highlight the Zero Float Tasks
Certain tasks are critical for the project’s on-time completion. Therefore, you must avoid tempering those deadlines as much as possible. Otherwise (this applies to the free float values, too), they might negatively affect the project’s end date.
To avoid such errors, there are several check-ups you can perform. For example, start by comparing the total float and free float values. Note that the activity can have a total float value greater or equal to its free float time.
So, to stay on the critical path, ensure no activity has a free float value larger than the total float. Also, negative numbers should not appear for any scheduled activity.
Forward Pass in Project Management – Potential Issues
Forward pass in project management is about securing an optimal project duration. It includes grouping early start dates and aiming for short task duration. However, there are a few possible pitfalls lying in wait.
Miscalculations: Project managers can sometimes oversee a key aspect. Hence, such an error will upset the integrity of the entire initial plan. Only a prolonged review period can catch such mixups on time. That also warrants another planning period to iron them out.
External conditions: You might miss a deadline due to various external developments. Things like sudden power outages or bad weather can halt any workflow. These are often hard to predict and prepare for. However, once the project team is aware of them, they can work on damage control.
Easy to get yourself into a corner: A streak of missed deadlines can keep on multiplying itself. As such, they can throw you off from the initial outline completely. Even if you opt to make quick adjustments, you should do so cautiously. That means finding the time to craft another basic plan and all that goes with it. So, neither solution is cost-effective.
If you liked this article talking about forward pass in project management, you should check out this one about project management for non-project managers.
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