T-Define Work Package or Task Dependencies
Updated: Nov 6, 2021
All projects have some dependency. Identify, understand, & manage the key dependencies.
Creating the Network Diagram With Post-it Notes:
Identifying, tracking, & continuously updating the dependency between work packages is a significant part of any project.
The sequence or dependency of the work i.e. knowing what comes before & what follows will determine the project’s schedule.
The more work that can be done in parallel the shorter the project, the more work in a linear sequence the longer the project.
There are two kinds of time associated with project work, duration and work effort.
Work Effort – The amount of time required to perform a task for all resources involved in the task (work effort drives the labor cost)
Duration – The available calendar time required to perform the work for the assigned resources. (duration drives the project schedule)
The path with the longest duration i.e. calendar time, it Is the project schedule.
The critical path can change as the work changes throughout a project, and it needs to be monitored & managed
The Network Diagram produces a calculated schedule based on data.
A particular work package may require 4 hours of work effort, 2 hours each for 2 resources, but it may be spread out over 8 calendar work days
The dependency of the work within small projects can be easily identified.
The tool for identifying dependency in medium to large project is the Network Diagram.
Determining task dependency is a skill every project manager & team member needs.
The most effective way to create the network diagram for a project is to facilitate the core team in building the network using post-it notes
When schedule is a critical requirement we recommend creating a graphical Network Diagram with post-it notes before entering the information into any software.
The graphical Network Diagram is used to identify work sequence & dependency
Not all projects need a graphical Network Diagram.
Creating & maintaining a graphical Network Diagram takes time, however it produces clarity, engagement, commitment, & a calculated schedule
All projects need work sequence & dependency
Sometimes a Network Diagram may only be needed to clarify a specific portion of a project
Graphical Network Diagram is needed when:
The project is Large & Complex
It’s critical to the organization
There are specific schedule constraints
Specific cost constraints
Specific quality requirements
Differences of opinion regarding work sequence & dependency
Creating the Network Diagram With Post-it Notes:
Put sufficient flipchart paper landscape on a flat wall surface .
By positioning the post-its on flipchart paper you’ll be able to roll up the flipchart paper & move your diagram as your team continues to work on it.
Overlap the pages so that when you connect the work packages you’ll be able to draw lines across the pages.
Record all work packages on post-it notes and initially just get all work packages up on the flipchart paper so you can see what you have, identifying the specific dependencies will unfold as you follow the recommended steps.
This is an iterative process
The Network Diagram identifies the critical path. The Critical Path in project management terms is not necessarily the English definition of the word critical, it's simply the longest path
You’ll be brainstorming what comes before & what comes after each work package & inserting the connecting lines
As you do this leave space between each item so you have room for the lines
Building the network diagram will help identify work packages that may need to be added or modified
As you create the network ignore any predefined schedule assumptions or requirements. Creating the schedule will be the next step.
Ideally you would want the person or persons who will be doing or managing the work participating either as you create the network or validating it later.
Building the Network Diagram:
Record all Tasks and/or Work Packages on Post-it notes
Add a post-it for Start Project on the left & End Project on the right
Initially position Work Packages in rough relative sequence
Add significant milestones to identify progress, milestones = 0 duration & effort, they identify significant accomplishments
Connect all Work Packages validated by the work owners
Brainstorm duration & work effort with the owners using a consistent metric for each work package. For a several week project you might use hours, for a several month project you would use days
Identify the longest duration path, that's the Critical Path
Add the duration of longest / Critical Path to determine the project’s end date
Add the work effort to determine the total labor required
Have the team perform a sanity check. Does it feel right, does it make sense?
Very often when schedule and labor cost isn't critical the network is used to understand dependencies, i.e. what comes before and what comes after each work package.
For critical projects do this work for as long as is comfortable, 1 – 2 hours & come back to it at another time.
If you have access to project management software that includes dependencies you can now enter your information into the software & let it calculate the critical path.
Whether you calculate it manually or have software do it, by highlighting the critical path in red on your flipchart paper you’ll have a tool to do what-if analysis that can otherwise be cumbersome in most project management software.
When project management software that includes dependencies determines your schedule it will use the project start date, the working days & hours for each individual resource & any non-working or holidays that have been entered. Not understanding how the software calculates the schedule can be confusing.
Defaults in the software may be set that appear to cause surprises. Doing it manually with post-it notes can overcome the confusion
Use the simplest approach that will meet your needs. If you’re not familiar with the software you can always continue using the manual post-it approach.
For critical projects invite people who were not part of creating the network to listen as you walk through & explain each work package to help validate the sequence & the completeness of your plan.
It’s typical for project customers & sponsors to set completion targets prior to allowing the project team to do the appropriate planning, they want it done fast.
Prior to identifying & validating work package dependency project schedules are at best an estimate or a guess.
If the Network Diagram’s calculated schedule is longer than required you now have the data to “Crash” or reduce project time.
Maintaining the network diagram every time there is a change can add overhead to managing the project.
For some projects it can be absolutely critical that each change in duration & dependency is monitored & managed.
For many projects creating the network at the beginning of the project to understand & define dependency and initial duration but not maintain the network may be enough. This is especially true when dependency doesn’t change but only duration changes. In these cases a manual process of hand shakes between work package owners with oversight from the project manager can be established to monitor & respond to the duration changes.