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

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

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

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

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

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

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

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

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

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.

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

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

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

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