1. 6.3 Sequence Activities
The process of identifying and documenting relationships between the project activities.
Every activity, except the first and last, must be connected to at least one predecessor and one successor
Milestones are generally connected to predecessor and successor activities with some exceptions, particularly when the milestone denotes an external dependency or a major event that is outside of the project
Simplified by using project mgt software
Occurs during Planning 1 2 3 4 5
Initiation
Planning
Execution
Close
Monitor
Control
Adapted from PMBOK 5th Edition

2. 6.3 Sequence Activities Inputs to Sequence Activities
Schedule Management Plan
Activity List and Attributes
Milestone List
Project Scope Statement
Enterprise Environmental Factors: Government or industry standards, PMIS, scheduling tools.
Organisational Process Assets: e.g.: policies, templates, learning from past projects
Adapted from PMBOK 5th Edition

3. 6.3 Sequence Activities Tools and techniques to Sequence Activities
Precedence
Diagramming
Lead &
Lag Times
(advanced technique)
Dependency
Determination
Adapted from PMBOK 5th Edition

4. Precedence Diagramming Method
This is one of the key techniques used to sequence activities in projects
It has become an industry standard and underpins project management software that produces both GANTT and PERT charts
Defines 4 types of logical relationships between activities
Finish-to-start (FS)
Finish-to-finish (FF)
Start-to-start (SS)
Start-to-finish (SF)
Initiation
Planning
Execution
Close
Monitor
Control
Adapted from PMBOK 5th Edition

5. Application of Interdependencies
Rule of Thumb Application
Finish to Start
95%
Start to Start
2.5%
Finish to Finish
Start to Finish
Not applicable
Many finish to start relationships are used in sequencing activities
Start to start and finish to finish are sometimes used to assist with planning

6. Finish-to-Start Relationships
The initiation of the successor activity depends on the completion of the predecessor activity
Translated this means…the start of the second activity is dependent on the completion of the first activity
In a GANTT chart this is depicted as an arrow from the end of the first activity pointing to the start of the second activity
Most common type of logical relationship between activities, sometimes this is a mandatory dependency, but often it is a preference for planning purposes
Activity 1
Finish-to-start
Activity 2
Adapted from PMBOK 5th Edition

7. Finish-to-Finish Relationships
The completion of the successor activity depends on the completion of the predecessor activity
Translated this means…the completion of the second activity is dependent on the completion of the first activity
It does not necessarily mean that both activities need to finish at the same time
In a GANTT chart this is depicted as an arrow from the end of the first activity pointing to the end of the second activity
Activity 1
Finish-to-finish
Activity 2
Adapted from PMBOK 5th Edition

8. Start-to-Start Relationships
The initiation of the successor activity depends on the initiation of the predecessor activity
Translated this means…the first activity must start before the second activity can start
Many people incorrectly assume that the activities need to start at the same time
In a GANTT chart this is depicted as an arrow from the start of the first activity pointing to the start of the second activity
Activity 1
Start-to-start
Activity 2
Adapted from PMBOK 5th Edition

9. Start-to-Finish Relationships
The completion of the successor activity depends on the initiation of the predecessor activity
Translated this means…the second activity can’t finish until the first activity starts
Very RARE and not available in some project management software, can normally be replanned as a finish to start relationship
In a GANTT chart this is depicted as an arrow from the start of the first activity pointing to the end of the second activity
Activity 1
Start-to-finish
Activity 2
Adapted from PMBOK 5th Edition

10. Example Relationships
Finish-to-start
Finish-to-finish
This means that Activity B cannot start until Activity A has completed. This is by far the most common relationship between multiple activities.
Activity A is “Create the Project Charter”
Activity B is “Obtain Project Charter approval from the Project Sponsor”
This finish-to-start relationship would say that we must create the Project Charter before we obtain Project Charter approval from the Project Sponsor
This means Activity A must finish before Activity B can finish. Assume you’re cooking dinner and you want the turkey to finish cooking before the potatoes.
Activity A is “Cook turkey”
Activity B is “Cook potatoes”
The finish-to-finish relationship says that the turkey must finish cooking (activity A) before the potatoes finish cooking (activity B). This relationship is based on the end times. They can each start whenever they need to, as long as they finish in this order.
Start-to-start
Start-to-finish
This means Activity A must start before Activity B can start. Assume that you are having your walls painted in one room and wallpaper is being hung in another room. You want to minimize the total disruption by having both activities happen at the same time.
Activity A is “Paint the walls”
Activity B is “Hang the wallpaper”
The wallpaper hangers may be ready to go (activity B). However, the start-to-start relationship says that they cannot start until the painting starts (activity A). This relationship is based on the activity start times. The end times of each activity are not related and, in fact, one activity could end at a much later time than the other.
Let’s assume that you want to fertilize your garden, but the plants must all be wet when the fertilizer is applied.
Activity A is to “fertilize the garden.”
Activity B is to “water the garden”
The start-to-finish relationship says we need to start watering the garden (activity B) first to get the plants wet. This activity must continue until the fertilizing starts (activity A).
This will ensure the plants remain wet until the fertilizer is ready to be applied. Note that you can start watering at any time and you can finish fertilizing at any time. The relationship only ties the start of activity A to the completion of activity B.

11. Types of Dependencies Mandatory Discretionary External
Contractually required or inherent in the nature of the work
Often involve physical limitations
Discretionary
Based on preferences and knowledge of best practice
Can be reviewed if fast tracking of project schedules is required
External
A relationship between project activities and activities outside of the project and outside of the project team’s control
Often regulatory
Initiation
Planning
Execution
Close
Monitor
Control
Adapted from PMBOK 5th Edition

12. 6.3 Sequence Activities Outputs of this process include –
Project Network Diagrams
High level PERT chart excluding time estimates, shows interdependencies between all activities
Project Document Updates
Changes to Activity Lists and Attributes
Change to the Milestone List
Changes to the Risk Register
Initiation
Planning
Execution
Close
Monitor
Control
Adapted from PMBOK 5th Edition

13. 6.3 Sequence Activities - Example
The example of the project to design and install a shed – we could draw a network diagram to represent the relationships between the tasks:
Sign contract
Design Shed
Obtain Council Approval
Council approval obtained
Check existing boundaries
Excavate site
Check underground cables
Note: these are all finish-start
Establish site services and amenities

14. 6.3 Sequence Activities - Example
We could also represent the information in a draft schedule:
Note: FS is finish-start. Other symbols may be: FF, SS or SF
Task ID
Phase/Task Description
Dependencies 1.
Design Phase 2.
Design Shed
N/A 3.
Obtain Councils Approval
2 (Design Shed) FS 4.
Council Approval Obtained
3 (Obtain Councils App..) FS 5.
End design phase
4 (Council Approval Ob..) FS 6.
Execution Phase 7.
Sign contract
5 (End design phase) FS 8.
Check existing boundaries
5 (End design phase) FS 9.
Check underground cable locations
10.
Establish site services and amenities
11.
Excavate site
7 (Sign contract) FS
8 (Check existing boun..) FS
9 (Check underground..) FS
10 (Establish site servic..) FS