As the owner of a content business, I have to make precise project estimates. If a project takes longer than estimated, I ultimately have frustrated customers and a deficit of other projects. I could also miss potential repetitions and recommendations.
In order to make a realistic estimate, it is not just my own time management and my capacity that I have to take into account. Swallowing such as illness, long internal ratings and non -unanimous expectations can derail a project.
How do I expect potential delays and integrate them into my planning? Let me introduce me with the Pert method.
Table of contents
What is pert?
Pert stands for program evaluation technology for program evaluation. It is a Project management Technology used for the first time In the 1950s From the US Navy and Booz Allen Hamilton. PERT uses a network diagram to use any activity in a project that should give relationships and dependencies between them and how long everyone should be given.
Pert against CPM
Pert is very similar to another technique that was introduced around the same time: CPM. CPM or Critical Path method uses a very similar assignment method as Pert to create the flow of activities in a project. The main difference is the main calculations.
CPM uses a deterministic approach with just one best -time estimate. Pert, on the other hand, uses a probabilistic approach that is taken into account in three different time estimates in its formula.
CPM is best used for projects with repeatable, predictable time, while pert is better for those with new or unpredictable activities. CPM can also be used to estimate costs and time.
The advantages of PERT analysis
I tried a lot of project management systems, from Gantt to Kanban to Bottom-Up estimates. There are so many ways to plan and optimize your project planning. Here is the reason why I found Pertabil.
1. More realistic time estimates
One reason why I like Pert is that it takes variables into account.
Among consultants I have heard a saying that even if you do the best estimation calculation in the world, you should still add 10% more because projects always take longer than you think.
Variables such as feedback delays, days outside the office and the creep-creep can easily give a service business.
The PERT formula calculates a weighted time estimation, whereby the most optimistic estimate and the most pessimistic estimate are taken into account – and the most likely time duration is calculated.
2. Visualizes the activities flow
I am a visual person, so I love being able to see that Project phases from start to finish. A PERT analysis enables me how every step works together in a project. I also like that I can see the tasks, especially where parts of a process get out and take place at the same time with other tasks.
3. Identified bottlenecks and possibilities
Both Pert and CPM are good to find the critical path or the sequence of essential steps through a project. Visual flows visual river also shows me where projects can have a bottlenecks. For example, production cannot progress without a strategic planning step or the approval of the customer and create potential bottlenecks.
As soon as I can see the assigned river, I can brainstorming options to optimize or emphasize the order of the activities how important a step for punctual delivery is.
How to use the Pert formula
Here is the Pert formula with which you can calculate the estimated time for a project:
Estimated time = (optimistic time + (most likely time x4) + (pessimistic time)) / 6
Or to write it better:
Pert formula example
Let’s take a joint project that I do for a customer: start a new website. Most of the time, a simple ten -page website would take six weeks. Since everything moves quickly, this could only take five weeks.
If there are many delays, e.g. For example, the customer who is longer than expected to send content and review pages can take up to 12 weeks.
In this scenario:
O (optimistic time) = 5 weeks
M (most likely time) = 6 weeks
P (pessimistic time) = 12 weeks
This is what it looks like in the formula: (5 + (6×4) + 12) / 6 = 6.83
By using the PERT formula, I found that the most likely time until the completion is 6.83 weeks. Since I always want to stay on the safe side of the delivery under My estimated schedule as a service provider, I will increase my estimated final time of six to seven weeks.
When I finish the project in six weeks, I will end up looking like a hero.
In Inside Pert diagrams: How I used one to estimate my website project
If you wonder how I came up with my first six-week estimate for the website project, I didn’t pull it out of the thin air. I didn’t just rely on my experience to create websites for customers, even though that was a factor. To achieve this number, I have depicted a Pert diagram.
A PERT diagram is a visual diagram that records all the steps that have to take place in a project, they diagramize in the order and show the dependencies between them.
A Pert diagram differs from other project management diagrams because they can record complex processes and steps and processes that take place at the same time.
1. Make my activities
To get started, I used lifting spots Pert diagram -Excel template To write down any activity that has to happen for A No-code hubspot website I create for a customer. This step is also referred to as a work breakout structure (WBS).
With the template I mapped every activity, e.g. B. “Creation of wireframes”, together with the person responsible, the most likely duration and then for optimistic and pessimistic duration.
I will ask my back-end consultant to add his time estimates, and I will find the information I need from my customers on a call? “
I also listed which dependencies for an activity have to take place. In most cases it is the task directly before her, but in some cases a task can trigger simultaneous steps (and possibly bottlenecks).
For example, the wireframes are a trigger for three simultaneous tasks: texts, collecting the visual assets and the side layout.
2. Creating my Pert diagram
You will also find that every task has a number, and here is the reason. Every task or activity corresponds to a “knot” in my diagram. Each knot is a rectangle that lists the activity name, the number and the most likely timeline. Arrows connect the nodes to display the flow of activity and the dependencies between tasks.
Phase I above shows the initial kickoff through wireframing and first searches for the customer. Then phase II shows the iterative stage, in which changes according to the customer’s feedback, the domain name and payment portals as well as the final examination and handover are connected.
3. Bonus: Identification of the slip time
After mastering the base diagram, I decided to take my Pert analysis one step further. I have integrated some principles of CPM to calculate the slip time for every task. The period is a number that represents the maximum permissible delay for a task without affecting the final date of the project (measured on days).
For example, if my customer needs three additional days to send me photography for the website, this is not delayed by the entire project, since the start -page layout lasts and has a certain time.
In this case the slack time = 3. But if the first look at three days is delayed, the entire project is delayed by three days, since no work without client input can run. In this case the slack time = 0.
You can draw a line – or a critical path – through your diagram and highlight the tasks with a difficult time from zero to show which path is most critical.
Pert diagram examples
There are many different ways to design a Pert diagram, but the basic concept is the same. I tried a few templates and wanted to share the best I found.
Drift Kings Media Pert diagram: for each business project
This is the template I started with, and I love it because they are available in four popular tools that everyone is used: Excel, PowerPoint, Google Sheets and Google Slides.
You can download or copy the template in minutes and simply add, move and edit modes to meet your requirements. This Pert example is ideal for business projects such as marketing campaigns, website or app development or a new setting.
Miro Pert diagram: estimate of a development project
In this Pert example, Miro’s template shows how you can appreciate a technical project such as hardware or software development. In the diagram there is a clear starting point and a clear end point. I can see which tasks are carried out at the same time and which general power current.
I like Miros Clean pictures and easy to use, drag-and-drop interface. It is also easy to work with my teammates in real time and leave comments or even audio notes.
Edrawmax Pert diagram: Create a house
I like this Pert Chart example because it is easy and it is an example that everyone can understand -to build a house! This variation of Edrawmax puts the task number in every knot and uses the arrows to display the activity and duration.
I like it is easy to adapt and add shapes and arrows to the diagram manufacturer. This example is better for simpler projects.
If you want to try this or your other templates, you can download Edrawmax And start for free.
How Pert helps me to run a more efficient and profitable business
There is no magical formula in a service business to estimate how long a project will be Strictly speaking Take, but Pert is about as close as possible.
By logging my activities in a WBS and then starting everything step by step, I can understand the process as a whole.
This gives me a probabilistic time estimation to quote a customer and enables me that my timeline and where there is no.
If I give a realistic time estimate, it is a win-win situation. My customers can better manage the expectations of the stakeholders and plan the business results around the timeline, while I like to run a less chaotic, efficient business.