Chapter 6 - Schedule Management Flashcards
Plan Schedule Management process
- Involves documenting how you will plan, manage, and control the project to the schedule baseline, and how you will manage schedule variances
Answers questions like:
- What approach will we take to plan the schedule for the project? Who will be involved?
- What processes and procedures will we use to create the schedule?
Key output of the Plan Schedule Management process?
Schedule management plan
Schedule management plan
- Part of the PMP
- Helps make the estimating and schedule development process faster by speciyfing how you will plan, manage, and control the project
Define Activities process
Taking the work packages created in the WBS and decomposing them into the activities that are required to produce the work package deliverables
When decomposing work packages, how do you know when you’ve decomposed enough?
Activities should be at a level small enough to estimate, schedule, monitor, and control
What happens after you define acitivites, i.e., decompose work packages?
Sequence activities
What do you need to define activities?
- Schedule management plan - gives info about approved methodology for scheduling
- Scope baseline - provides info about what is included in project scope
- OPAs
When is decomposition used for Define Activities process in schedule management, and for Create WBS process in scope management?
Define Activities
When work packages are decomposed into activities to produce them
Create WBS
When deliverables are decomposed into smaller deliverables
Rolling wave planning
- Plan to a higher level, and then develop more detailed plans when the work is to be done
- In other words, plan activities to the detail needed to manage the work just before you are ready to start the project
- Form of progressive elaboration
What does the Define Activities process result in?
An activity list, which includes all activities required to complete the project, and details regarding project activities
Sequence Activities process
Taking the activities and sequencing them in the order in which the work will be performed
What does sequencing activities result in?
A network diagram
What does a network diagram represent/show?
- In it’s pure form, it shows just dependencies, i.e., logical relationships
- If activity duration estimates and leads and lags are included, it also shows the critical path
- If plotted out against time, it shows a time scaled schedule network diagram
How are most network diagrams created today?
- Using the Precedence Diagramming Method (PDM)
- Old method = Graphical Evaluation and Review Technique (GERT)
Precedence Diagramming Method (PDM)
- Nodes, a.k.a. boxes, represent activities
- Arrowsshowactivity dependencies
Different types of logical relationships between activities
- Finish to start (FS)
- Start to start (SS)
- Finish to finish (FF)
- Start to Finish (SF)
Finish to start (FS)
- An activity must finish before the successor can start
- MOST COMMON!
- Example: you must finish digging a hole before you can start planting the tree
Start to start (SS)
- An activity must start before the successor can start
- Example: you must start desgining in order to have enough of the design completed to start coding
Finish to finish (FF)
- An activity must finish before the successor can finish
- Example: you must finish testing before you can finish documentation
Start to finish (SF)
- An activity must start before the successor can finish
- RARELY USED
Types of dependencies
- Mandatory dependency (hard logic)
- Discretionary dependency (preferred, preferrential, or soft logic)
- External dependency
- Internal dependency
Mandatory dependency (hard logic)
Inherent in the nature of work, or required by a contract
Discretionary dependency (preferred, preferrential, or soft logic)
- The way an organization has chosen to have work performed
- You can change this type of dependency if necessary
- Important when analyzing how to compress the schedule to decrease project duration, i.e., fast track the project
External dependency
Based on the needs or desires of a party outside the project (for example, government, suppliers, etc.)
Internal dependency
Based on the needs of the project and may be something the team can control
Who identifies what type of dependencies?
- Project team = mandatory and discretionary
- PM = external and internal
Lead
Used to indicate that an activity can start before its predeccesor activity is completed
Lag
Waiting time inserted between activities
Path convergence
When an activity has two or more activities directly preceding it, i.e., two activities run into the same activity once complete
Path divergence
When an activity has two or more successor activities directly following it
What do path convergence and divergence indicate?
Greater risk within impacted activities
Estimate Activity Durations process
When the activities have been defined and sequenced, the next step is to estimate how long each activity will take
What do resources need in order to come up with activity duration estimates?
- Activity list and attributes
- Assumption log
- Learned lessons register
- Resource breakdown structure
- Resource requirements
- Project team assignments
- Resource calendars
- Risk register
Resource breakdown structure
Represents categories of resources
Resource requirements
Indicates the skill levels of resources
Resource team assignments
Include the number and experience level of resources
Resource calendars
- Provide information on when key resources with specialized skills will be available
- If resources aren’t available within time frame, you may need to add extra time to some activity estimates to allow lesser experienced resources to do the work
Padding
- Extra time or cost added to an estimate because the estimator does not have enough information
- It’s a blind guess!
When there are many unknowns and info required to clarify the unknowns is unavailable, how should you address additional time or funds?
Additional time or funds should be addressed via reserves
One point estimating
- Estimator submits one estimate per activity
- Problematic, as estimates may be based on expert judgment, historical information, or simply a guess
- Easy way to illustrate how to draw network diagrams and find the critical path
- Allows for quick calulation on the exam!
Negative effects from one point estimating
- Encourages padding
- Doesn’t provide enough justification
- Produces a schedule that no one believes in
- Can make estimator look unreliable if activities take more or less time than orginally estimated
Analogous estimating (top down)
- Using expert judgment AND historical info to predict the future
- Can be done at various times throughout the project, and the level of accuracy depends on how closely the project or activity matches the historical data used
Parametric estimating
- Involves creating a mathematical equation using data from historical records or other sources to create estimates
- Analyzes relationships between historical data and other variables
Regression analysis (scatter diagram)
- A diagram that tracks two variables to see if they are related
- Diagram is then used to create a mathematical formula to use in future parametric estimatnig
Three point estimating
Estimators give an optomistic (O), pessimistic (P), and most likely (M) estimate for each activity
What does a wide range between O and P estimates indicate?
Indicates uncertainty, i.e., risk, associated with the activity
Triangular distribution (simple average)
Equal risk weighting
(P + O + M) / 3
Beta distribution (weighted average)
Beta distribution gives stronger consideration to the most likely estimate
(P + 4M + O) / 6
When to use triangular distribution vs. weighted?
- Minimal experience/historical info = triangular
- More info/historical info = beta
Beta activity standard deviation
- The possible range for the estimate, i.e., +/-X
- (P - O) / 6
- The GREATER the deviation, the GREATER the risk
Bottom up estimating
- Creating detailed estimates for each part of an activity or work package
- Requires an accurate WBS
Contingency reserves
- Allocated for the identified risks remaining after the Plan Risk Responses process (known unknowns)
- Expected values of each contingency plan are added together to create a schedule contingency reserve
Management reserves
- Additional funds and time to cover unforeseen risks that could impact the project’s ability to meet the schedule (unknown unknowns)
- Require a formal change request in order to utilize
Difference between padding and reserves
- Padding utilizes broad guesses
- Reserves utilize the necessary info to reliably caclulate what additional time or funds the project may need
Process to achieve a realistic schedule/budget
- Analyze the work needed to complete the project
- Estimate the duration/cost of the work, and calculate an end date and budget
- Optimize the date and budget, and compare results to schedule and budget constraints
- If there’s a difference, analyze the project and provide options on how to change it to meet constraints, i.e., balance constraints
Schedule model
- Includes all the project data that will be used to calculate the schedule, such as activities, duration estimates, dependencies, and leads and lags
- Project schedule is the output of the schedule model (consolidates all the data into one schedule)
Critical path method
- Determining the longest duration path through the network diagram, the earliest and latest an activity can start and finish
- The critical path is the longest duration path through a network diagram, and also has ZERO FLOAT
Near critical path
- The path closest in duration to the critical path
- The closer the near critical path and critical paths are, the GREATER the overall schedule risk
Total float
- The amount of time an activity can be delayed without delaying the project end date or an intermediary milestone, while still adhering to any imposed schedule constraints
- PRIMARY TYPE OF FLOAT
Free float
Amount of time an activity can be delayed without delaying the early start date of its sucessor(s) while still adhering to any imposed schedule constraints
Project float (positive total float)
Amount of time a project can be delayed without delaying the externally imposed project completion date required by the customer or management, or the date previously committed to by the project manager
Float calculations
“There is a start fomula and a finish formula, and we always begin late”
Start formula (forwards pass)
Float = LS - ES
Finish formula (backwards pass)
Float = LF - EF
Draw a network diagram box (activity)
When dealing with path convergence in a forward pass, how do you decide which estimate to use?
In forward pass, always use the later EF of the predecessing activities to use as the ES for the succeeding activity, since the succeeding activity can’t start until both predecessing activities are complete
In order to begin the backwards pass, you first need to determine the LF for the last activity. How do you know what the LF is?
In a backwards pass, the LF is always the duration of the critical path
When dealing with path convergence in a backwards pass, how do you decide which estimate to use?
In backward pass, always use the earlier LS of the succeeding activities to use as the LF for the preceeding activity, since the preceeding activity must be finished before the suceeding activity can start
Calculation checks for finishes and starts
Forward Pass
EF = D + ES
ES = EF - D
Backward Pass
LF = D + LS
LS = LF - D
Fast Tracking
- Adjusting the network diagram so critical path activities that were originally planned to be completed in a series are replanned to be done in parallel
- In other words, instead of performing activities A and B after one another, perform them at the same time to save time and money
- Often results in rework, increased risk, and requires more attention to comms
Crashing
- Adding or adjusting resources in order to compress the schedule while maintaining the original project scope
- Results in increased costs and may increase risk
- Trades time for money
What is the first thing to do when there is negative float, i.e., your estimated completion date is after the desired date?
Analyze what could be done about negative float by compressing the schedule
What is the preferred method to deal with schedule compression?
Review risks and re-evaluate!
Impacts of fast tracking
- Increased risk
- Added management time for PM
Impacts of crashing
- Increased costs
- May add management time for PM
- May add risk
Impacts of reducing scope
- May save cost, resources, and time
- May negatively impact customer satisfaction
Monte Carlo Analysis
- Technique that uses computer software to simulate the outcome of a project based on the three point estimates for each activity
- Can help deal with path convergence
Can tell you the following:
- Probability of completing the project on a specific day
- Probability of completing the project for a specific cost
- Probability of any activity actually being on the critical path
- Indication of overall project risk
Resource leveling
- Used to produce a resource-limited schedule
- Lengthens the schedule and increases cost to deal with a limited number of resources
- Results in a more stable number of resources used on your project
Resource smoothing
- Modified form of resource leveling
- Resources are leveled only within the limits of the activity floats, so the completion dates of activities are not delayed
Outputs of Develop Schedule process
- Project schedule
- Schedule baseline
- Schedule data
- Change requests
- PMP updates
When to use different presentation formats:
Network Diagram
Milestone Chart
Bar Chart
Network Diagram
To show interdependencies between activities
Milestone Chart
Report to senior management
Bar Chart
Track progress
Report to the team
