Do You Have a reliable Project Schedule?
How do you know if your project schedule is going to be good enough to carry you through the work? Schedule analysis is the tool that experienced project teams use to check whether the schedule is built in a way that supports delivery and is being used in a way that helps people stay up to date with progress.
So what should you look for in a schedule? We carry out schedule analysis for clients all the time, and one of the tools for guidance that we use is the GAO Schedule Assessment Guide (GAO-16-89G).
It shares a huge range of scheduling best practices. It also describes the four characteristics of a reliable project schedule as being:
- Comprehensive
- Well-constructed
- Credible
- Controlled
We refer to that as the 4C’s of scheduling (even though it’s a bit of a stretch for “well-constructed”).
The 10 best practices documented in the guide each map to one of these four characteristics, so they are a good starting point for consideration when you begin to think about schedule analysis.
Below, we provide a quick overview of what the different characteristics look like for schedulers.
Comprehensive
A comprehensive schedule is one that:
- Captures all the activities as defined in the Work Breakdown Structure
- Has resources assigned to each activity
- Has durations for each activity.
Your project schedule should include all the work that is required, even if those tasks are not necessarily being performed by project team members. That’s a way to avoid leads and lags which sometimes mask work being performed by others.
Each activity from the WBS should be reflected on the schedule with the appropriate resources allocated as required. Every activity should have a start and finish date which provides the duration.
Well-constructed
A well-constructed schedule has:
- All activities sequenced logically
- A valid critical path
- Reasonable total float
- Schedule documentation that explains and justifies scheduling decisions.
Use the predecessor/successor logic and dependencies within Primavera P6 or your project management software to create a dynamic schedule. When we carry out schedule reviews for clients, we check for awkward logic and try to keep things as streamlined as possible.
Most schedules end up with some flexibility, and that’s reflected in the amount of float. You don’t want too much or too little, so sometimes this is a professional judgement call. But it should feel right, and a professional scheduler can give you a sense of whether the available float is reasonable for the work.
Credible
A credible schedule is one that:
- Has tasks in the right order, leading up to a verifiable deliverable
- An appropriate mix of deliverable-driven tasks and management activities
- Inspires confidence in the team because they know schedule risk has been addressed.
Credibility is perhaps the hardest thing to achieve in a schedule, because it relies on so many different things, not least the scheduling best practices employed by the people entering data into the tool.
It’s also one of the harder things to do in practice, because a credible schedule should be horizontally traceable. In other words, the work is structured in a sensible order and naturally leads to completing a deliverable (or an aggregated set of deliverables). Vertical traceability is also required: when you read down the schedule, the activities make sense in relation to the dates and governance points. Our scheduling best practices course reviews exactly what your schedulers should be doing in more detail.
Schedule risk analysis is something that should be carried out to add another layer of credibility and confidence to the plans. Adjustments can be made based on the level of schedule risk anticipated, and then that can be kept under review as the work progresses. Contingency can be added as appropriate to mitigate risk where that is an appropriate response.
Controlled
A controlled schedule is one that is:
- Baselined for tracking against
- Regularly updated using data that reflects actual progress
- Managed with a configuration management process that handles changes.
Ideally, a working schedule should be left in the hands of people trained in how to do scheduling. We carry out scheduling services for many clients so they can focus on using their expert resources to do the actual delivery, while we maintain and update the Primavera P6 plans on their behalf. Then they don’t have to worry about not having skilled schedulers on the team, or having to recruit someone for a specific contract.
The first thing we focus on with controlling a schedule is to make sure that the updates reflect actual progress, using real-time (or as near real-time as possible) data from the people doing the work. The forecasted dates may need to be updated and the schedule logic should drive this instead of manual updates – so this is where it pays off to have a well-constructed schedule.
The other major activity that takes place during execution is managing variances. We compare the actual performance to the baselined performance and assess variances. These then need to be managed, and depending on the magnitude of the variance, there may need to be a set of actions that follow on. A variance that doesn’t affect the critical path and is within tolerance may be managed easily by the project team. A trend that shows it is likely the project will fail to complete within the expected dates is something to monitor, and earned value management reports help here. A variance that pushes the project off course is something that needs escalating and communicating. Ideally, that kind of variance should not creep up on a team because active schedule management allows them to spot deviations from plan in advance.
That might seem like a lot when you review the characteristics of a good, reliable project schedule in the round, but really it’s the minimum required to ensure your project has robust foundations. If you want your plans to be realistic and accurate, it’s worth putting the work in upfront to create a schedule that allows you to drive the work forward with confidence. Or, have us do it for you!
When you have a reliable project schedule, everyone knows what they are supposed to be doing when, and clients trust you to get the job done.