Description
time management and why time management is necessary, what are the main culprits of wastage of time in the project, different tools and techniques to manage time, wideband Delphi Method. It also explains critical path method.
Project Scope Management
.
What is Time Management?
What is Time Management?
Definition:
?
The Predictable control an individual can exercise over a series of events.
What is Time Management?
? Time
management is the development of processes and tools that increase time-efficiency.
Why it is necessary?
?
What does Time (Self) Management ?Do for you? ?Do for your job? ?Do for you group? ?Do for your organization?
Time Wasting Culprits
Telephone Interruptions ? Inefficient Delegation ? Extended Lunches or breaks ? Cluttered Work Space ? Poorly run meetings ? Socializing on the Job ? Misfiled information
?
Time Wasting Culprits
Poor Planning ? Procrastination (putting off or delaying or deferring an action to a later time ) ? Waiting/ Delays ? Paperwork ? Junk emails ? Drop-In visitors ? Not Setting/ Sticking to priorities
?
What is Time Management?
Processes to ensure the timely completion of the project. Major processes ? Activity definition
?
Identifying the specific activities Documenting activity dependencies Estimating time to complete individual activities Create a project schedule Controlling changes to the project schedule
? ? ? ?
Activity sequencing
?
Activity duration estimating
?
Schedule development
?
Schedule control
?
Activity Definition (Planning)
?
Activity definition involves identifying and documenting the activities that must be performed in order to produce the deliverables and sub deliverables identified in the WBS.
Activity Definition…
Inputs
WBS Scope statement Historical Information Constraints Assumptions
Tools & Techniques
Decomposition Templates
Outputs
Activity List Supporting Detail WBS Updates
Inputs
? ?
?
? ?
Work breakdown structure ? Primary input Scope statement ? Project justification and objectives must be explicitly considered. Historical information ? Activities performed in previous projects should be considered Constraints ? Factors that will limit the team’s options Assumptions ? Factors considered to be true.
Tools and Techniques
?
?
Decomposition ? Similar to the decomposition of work as part of Scope Definition. ? Activities are explored instead of deliverables. Templates ? Activity list from previous projects or activity lists of a WBS element can be useful. ? Process descriptions in the quality manual.
Output…
?
?
Activity list ? All activities which will be performed during the project or phase. ? It should be organized in relation to the WBS to ensure completeness. ? Should include descriptions of each activity. Supporting detail ? Supporting detail of the activity list including assumptions and constraints should be documented.
Activity Sequencing (Planning)
?
Activity sequencing involves identifying and documenting interactivity dependencies.
? This
has to be done accurately in order to support later development of realistic and achievable schedules. ? Sequencing can be done by project management software or manual technique. ? Manual technique could be used in small projects or in initial phases of large projects when little detail is available
Activity Sequencing (Planning)
Inputs Activity Lists Product Descriptions Mandatory Dependencies Discretionary Dependencies External Dependencies Assumptions Constraints Tools & Techniques Precedence Diagramming Method Arrow Diagramming Method Conditional Diagramming Method Network Templates Outputs Project Network Diagram Activity List Updates
Inputs
? ?
Activity list
? Created
as an output of activity definition characteristics may affect activity sequencing.
Product description
? Product
?
Subsystem modules should be coded before integration test can be performed
? Should
be reviewed to ensure accuracy. in the nature of the work being done.
?
Mandatory dependencies
? Inherent
?
Baseline of a package is created after all the modules are unit tested.
Inputs
?
Discretionary dependencies – preferred logic
? Dependencies defined by the project management. ? Might be based on best practices or exceptional
cases.
?
Modules can be reviewed before compiled to improve productivity.
?
External dependencies
? Dependencies
involve relationships with non-project
activities.
?
Keyboard is required before testing the keyboard driver. Assuming the project objective is to build the driver only)
?
Milestones
? Milestone
events should be part of the activity sequencing
Tools and Techniques
?
Precedence diagramming method (PDM) – Activityon- node
? Nodes represent activities ? Arrows represent dependencies – precedence relationships ? Finish to start – from activity must finish before the to
activity can start
? Finish
to finish – from activity must finish before the to activity can finish
? Start
to start – from activity must start before the to activity can start
to finish – from activity must start before the to activity can finish
?
? Start
Can you think of an example?
PDM Network Chart
Tools and Techniques
?
Arrow diagramming method – Activity-onarrow
? Arrows
represent the activities ? Nodes represents events ? Only finish-to-start dependency is represented
Events versus Activities
?
Event = a point in time
? has
no duration ? e.g the start or end of an activity
?
Activity = a task or an action with a recognizable start and finish and a duration
Tools and Techniques
?
Conditional diagramming methods
? Allow
?
non-sequential activities such as loops or conditional branches.
?
Acceptance test that must be repeated until product is acceptable Design update task is required only if the review requires revision.
? System
Dynamics Modeling ? Control Flow Diagrams
?
Network templates
? Standardized networks can be used … ? For entire or part of the project ? Portions of a network are called subnets
Outputs
?
Project network diagram
? Depicts
?
the project`s activities and dependencies among activities.
Project Network Diagram is NOT a PERT chart. ? PERT technique relates solely to time scales and virtually identical to CPM.
?
Activity list updates
? Preparation
?
of the network diagram may clarify the need
For more detailed activities ? To redefine activities
Activity Duration Estimating (Planning)
?
Estimating the time required to complete each required activity. ? Activity duration estimating involves assessing the number of work periods likely required to complete identified activity. ? The person or group who is most familiar with the nature of specific activity should make or at least approve the estimate. ? While making the activity duration estimate one needs to take into consideration the elapsed time as well.
Activity Duration Estimating (Planning)
Inputs Activity List Assumptions Constraints Resource requirement Resource capability Historical Information Tools & Techniques Expert Judgment Analogous Estimation Simulation Outputs Activity Duration Estimates Basis of Estimates Activity List updates
Inputs
? ? ? ?
Activity list Constraints Assumptions Resource requirements
? Duration
?
of activities are usually related with the resources assigned to them.
?
Coding of a 100 LOC class can be performed by 1 programmer in one day By 2 programmer in two days!
?
Resource capabilities
? The
?
duration of activities are also related with the capability of the resources
Productivity of programmers has the ration 1:10
Inputs
?
Historical information
? Project
?
files
Contain information related with estimation of activities at team, individual levels.
? Commercial
?
duration estimating databases
Software cost/effort/duration estimation tools usually based on and include data on significant number of projects
? ? ? ?
COCOMO COPMO SLIM Knowledge Plan
? Project
?
team knowledge
Although not very reliable could be the only source of information for many software projects.
Tools and Techniques
?
Expert Judgment ?Expert judgment guided by historical information is frequently the only possibility. ?A structured approach to minimize judgment errors is called Wideband Delphi method
Wideband Delphi Method
?
Several experts individually produce estimates then those estimates converge on a consensus estimate. ? 1. A group of experts given source documents and estimation form ? 2. Meeting 1: discuss project goals, assumptions, estimation issues ? 3. Each anonymously list tasks and estimated sizes ? 4. Estimates are tabulated by a moderator and given back to experts. Personal estimate is identified others anonymous. 0 20 40 60 80 100 X X* X! X X X*= Your Estimate, X!=Median Estimate ? 5. Meeting 2: discuss results ? Bring insight to the problem ? 6. If possible, reach a consensus estimate ? If no consensus, break until you can gather additional data, then goto step 3
Tools and Techniques
?
Analogous estimating – top-down
? Using
?
the actual duration or effort of a previous similar activity as the basis.
Suitable for early phases ? Similarity of activities should be high ? Individuals can calibrate the results
?
Quantitatively based durations – bottom-up
? Activity
effort = Quantity * Productivity
Output – Activity Duration Est.
Activity duration estimates ?Should always include the range of possible results. ? Basis of estimates ?Assumptions made in developing the estimate ? Activity list updates
?
Top-Down Software Estimation Models
COnstructive COst MOdel
63 TRW projects size range from 2,000 SLOC to 966,000 SLOC ? Heterogeneous: Incorporates different application domains. ? There are three COCOMO levels
? Basic ? Intermediate (the most popular) ? Detailed
?
?
The different versions of the model represent different levels of detail or precision
Problems with CoCoMo
?
?
?
? ?
Ignores customer attributes ? Skill, Cooperation, Knowledge, Responsiveness ? “You cannot have a level 3 organization with a level 1 customer.” Oversimplifies the impact of security issues Ignores software safety issues Ignores SW development environment Ignores personnel turnover levels
CoCoMo Works Well
?
COCOMO works well
? If
you feed actual data from many real programs,
? ?
you can often find a set of Cocomo constants and adjustment factors that fit your organization well sometimes you need to add unique adjustment factors associated with your organization
?
?
?
COCOMO is a simple, exponential curve fit algorithm -- many situations can be fitted to exponential curves As long as new projects are not dramatically different in size, complexity, or process, COCOMO can be quite valuable as an estimating tool Better not to rely on just one estimation model
Bottom-up Estimation
?
Effort = Size / Productivity ?Size can be represented by Function Points ?Productivity can be defined as FP / Person-Months
Schedule Development (Planning)
?
Schedule development means determining the start and finish dates for project activities. ? These have to be realistic for the project to finish on schedule. ? Schedule development process have to iterated with the required inputs from the different process prior to the development of schedule
Schedule Development
Inputs Tools & Techniques Outputs
Project Network Diagram
Activity Duration Estimates
Mathematical Analysis
Schedule Compression
Project Schedule
Supporting Detail
Resource Requirement
Resource Pool Description Calendars
Simulation
Resource Leveling Project Management Software
Schedule Mgmt Plan
Resource Requirement Updates
Leads & Lags Constraints Assumptions
Inputs
? ? ? ?
Project network diagram Activity duration estimates Resource requirements Resource pool descriptions
? Knowledge of availability ? what resources, ? when, ? in which pattern.
of
?
Calendars.
? Identification of periods when work is allowed ? Project calendars – effect all resources ? Resource calendars – effect specific resources
Inputs
?
Constraints
? Imposed
dates ? Key events or major milestones
Assumptions ? Leeds and lags
?
? Activity
dependencies may require lead or lag specifications ? Completion of a training and application of a tool might require to specify 2 day lag.
Tools and Techniques
?
Mathematical analysis
? Calculating
early and late start and finish dates for all project activities with no resource constraints. ? The results are not the schedule but indications of scheduled dates. ? Critical path method (CPM)
?
?
?
?
Calculate early and late start and finish date for each activity, based on sequential network logic and single duration estimate Focus is to determine activities which has the least schedule flexibility.
Start and Finish Times
Earliest start (ES) ? Earliest finish (EF) = ES + duration ? Latest finish (LF) = latest task can be completed without affecting project end ? Latest start = LF - duration
?
Critical Path Method
Forward pass: ? Initial conditions for the first activity
?
? EST
=0 ? EFT = EST + Duration
?
For all subsequent activities
? EST
= maximum EFT of preceding activities ? EFT = EST + duration
Critical Path Method
?
?
?
Backward pass: Terminal condition for the last activities: ? LFT = EFT ? LST = LFT - duration For all previous activities: ? LFT = minimum LST of following activitie ? LST = LFT - duration
Float
Float = Latest finish - Earliest start – Duration ? Any activity with the float 0 is critical
?
Tools and Techniques
?
?
Program evaluation and review technique (PERT) ? Calculate project duration based on ? sequential network logic and ? weighted average duration estimate It uses distribution?s mean instead of the most likely estimate.
Tools and Techniques
Tools and Techniques
?
? ?
Duration compression ? Looking for ways to shorten the project schedule without changing the scope. ? Crashing ? By analyzing cost and schedule trade-offs determine greatest compression for minimum cost. ? Fast tracking – co-engineering ? Doing activities in parallel that would normally be done sequentially. Simulation Resource leveling heuristics ? Mathematical analysis does not necessarily produces a manageable schedule. ? Heuristics can be used to level resources ? „allocate scarce resources to critical path activities first?
Tools and Techniques
?
Project management software
? Automate
the calculation of mathematical analysis and resource leveling. ? Enables what-if analysis ? Very flexible to report project schedule
Output
?
Project schedule
? Includes
at least planned start and expected finish dates. ? Project schedule considered preliminary till confirmed resource assignments. ? Project schedule representation
Project network diagrams ? Gantt charts – milestone charts ? Time scaled network diagram
?
Project Network Diagram
Gantt Diagram
Output
?
Supporting detail
? All
identified assumptions and constraints are included ? Resource – human resource - requirements by time period ? Alternative schedules ? Schedule risk assessment
?
Schedule management plan
? Defined
how changes to the schedule will be managed. have significant effect on preliminary estimates
?
Resource requirement updates
? May
Schedule Control
?
Schedule change control is concerned with ?Influencing the factors which create the Schedule changes to ensure that they are beneficial ?Determining that the Schedule change has occurred ?Managing the Schedule changes when they actually occur
Schedule Control
Inputs Project Schedule Performance Reports Change Requests Schedule Management Plan Tools & Techniques Schedule Change Control System Performance Reports Additional Planning PM Software Outputs Schedule Changes Corrective Actions Lessons Learned
Inputs
?
Project schedule
? The
schedule baseline, is a component of the overall project plan. ? It provides the basis for measuring and reporting schedule performance.
?
Performance reports
? Provide information on schedule performance ? which planned dates have been met and which have not.
?
Change requests
? May
occur in many forms ? Changes may require extending the schedule or may allow accelerating it.
?
Schedule management plan
Tools and Techniques
?
Schedule change control system.
? Defines
the procedures by which the project schedule may be changed. ? It includes the paperwork, tracking systems, and approval levels necessary for authorizing changes. ? Schedule change control should be integrated with the overall change control system
?
Performance measurement.
? Performance
measurement techniques help to assess the magnitude of any variations ? Enables to decide if the schedule variation requires corrective action.
?
For example, a short delay on a critical or near-critical activity may require immediate action.
Tools and Techniques
?
Additional planning
? Changes
may require new or revised activity duration estimates, modified activity sequences, or analysis of alternative schedules.
management software enables
?
Project management software.
? Project
?
tracking planned dates versus actual dates and ? forecasting the effects of schedule changes
Outputs
?
Schedule updates
? Schedule
updates may require adjustments to other aspects of the overall project plan. ? Revisions are changes to the scheduled start and finish dates in the approved project schedule. ? Schedule delays may be so severe that “rebaselining” might be needed.
?
Corrective action.
? Often involves expediting. ? Special actions taken to ensure
completion of an activity on time or with the least possible delay. causes of variances, the reasoning of corrective actions etc., should be documented
?
Lessons learned.
? The
Time Management Problem
?
Thank You…
Time Management Problem
?
? ?
How to draw a project management network for the activity and predecessor information provided. First, remember the two questions you want to answer: When will the project be done, and Which activities will require our personal attention
Activity
Predecessors
A
B C D E F G
--A A B,C D D,E
Time Management Problem
?
With this information, we were able to draw the network as given below:
2 A D 4 F
1 B 3
C G E
6
5
Time Management Problem
?
?
?
? ?
Our next step is to collect the data that will tell us how long each activity will take. For CPM, this is a single number, called the NORMAL activity time. For PERT, you get three numbers, an OPTIMISTIC, a PESSIMISTIC, and a MOST LIKELY. These three are averaged together to get a single EXPECTED activity time. Whether you are using PERT or CPM, you end up with a single number to use and you use them the same way.
Time Management Problem
?
?
Whether you are using PERT or CPM, you end up with a single number to use and you use them the same way. For this example, the activity times are:
Activity A B C D E F G
Predecessors --A A B,C D D,E
Activity Time
5 6 4 7 5 8 3
Time Management Problem
We will use this information and the network we have drawn to calculate four numbers for each activity. These are: ? ES = the EARLIEST START time, or the earliest time the activity can start, allowing for all predecessor activities to finish. ? EF = the EARLIEST FINISH time, or the ES plus the ACTIVITY TIME. ? LF = the LATEST FINISH time, or latest time the activity can finish if all subsequent activity are to be started and finished on time. ? LS =the LATEST START time, or the LF minus the ACTIVITY TIME.
Time Management Problem
?
All of these numbers will be recorded on the network. The figure shown next is a key for interpreting the network , showing where each number should be placed.
Earliest Start Latest Start Activity Name Activity Time Earliest Finish Latest Finish
Time Management Problem
?
Now, using the key, the data given, and the network, we can begin to answer our questions. First, for each activity, enter the activity times you were given into the network, underneath the arrow, in the center:
2 A 5 1 B 6 3 E 5 5 4 C G 3 D 7 F 8 6 4
Time Management Problem
? ? ?
?
The DUMMY activity (the dotted line from node 4 to node 5) has no activity time, because it takes no time to complete. The DUMMY, remember, is simply used to show the precedence relationship of D before G. The next step is to complete a FORWARD PASS through the calculations. This means to start on the left, at node 1, and calculate the Early Start and Early Finish time for each activity. Since activities A and B have no predecessors, they can begin right away, so the ES is set equal to zero. As noted before, the Early Finish time is simply the activity?s Early Start plus the activity time written below the activity arrow.
5 A 0 1 0 B 6 6 3 E 5 5 5 4 C G 3 2 D 7 F 8 6 4
Time Management Problem
? ? ? ?
For example, A is the predecessor to D, so A must be finished before D can begin. Since the earliest finish for A is 5, then the earliest D can begin is 5. The same is true for C; the earliest C can begin is 5, because that is the earliest A can finish. However, we cannot determine the earliest start for E, because B and C must be completed, and we do not have the earliest finish for C shown on the network. The only two activities we can calculate are C and D, so we add the ES and EF for those two to the network:
5 A 0 1 0 B 6 6 5
2 5
5
D 7
12
4 F 8
4 C 9 3 E 5 5 G 3
6
Time Management Problem
? ? ?
Let us calculate ES and EF for remaining activities. F is rather simple, having only one predecessor - activity D - activity F can begin as soon as activity D is done, so the Early Start time for F is the same as the Early Finish time for D, or 12. The Early Start time for activity E requires a little common sense. B and C are the predecessors, so BOTH B and C must be done before E can begin. Therefore, take the larger of the Early Finish times for B and C, then record that as the Early Start time for E. For E, F, and the dummy, the EF time is calculated as before, by adding the activity time to the ES. This gives us:
5 A 0 1 0 B 6 6 3 9 E 5 14 5 5 4 C 9 12 G 3 2 5 5 D 7 12 8 F 20 6 12 4 12
Time Management Problem
?
?
ES and EF for the dummy are the same. This is because the dummy takes no time. The only reason for showing the ES and EF for the dummy is to make it easier to calculate the Earliest Start time for G. Since all the predecessors for G (E and D, through the dummy) have their earliest finish times shown, we compare their EF times (12 and 14) and select the largest as the earliest start time for G.
5 A 0 1 0 B 6 6 3 9 E 5 14 5 5 4 C 9 12 14 G 3 2 5 5 D 7 12 8 F 20 6 17 12 4 12
Time Management problem
? ?
? ?
Since F and G are final activities, we will be done at the later of their Early Finish times, which is 20. With this information, we can begin a BACKWARDS PASS through the network, calculating the Latest Finish and Latest Start times for each activity, beginning on the right with activities F and G, and moving to the left. If we are going to promise to have the project done at time 20, then clearly the Latest Finish we can allow for either of the final activities is 20. To get the Latest Start for any activity, simply SUBTRACT the activity time from the Latest Finish time.
5 A 0 1 0 B 6 6 3 9 E 5 14 5 5 4 C 9 12 14 17 G 3 2 5 5 D 7 12 12 4 12 12 8 F 20 20 17 20
6
Time Management problem
? ?
?
The backwards pass is a little trickier than the forward pass because you have to think about both predecessors and followers, but the logic is very similar. For example, both E and the dummy (representing D) must be done so that G can begin on time. Therefore, the Latest Finish for E and the dummy is the same as the Latest Start time for G. We cannot, however, determine the Latest Finish time for D, because both F and the dummy follow D and we have not yet shown the Latest Start time for the dummy. So, we next fill in the LF and LS for E and the dummy:
5 A 0 1 0 B 6 6 3 9 12 E 5 14 17 5 5 4 C 9 1712 14 17 G 3 2 5 5 D 7 1712 12 4 12 12 8 F 20 20 17 20
6
Time Management problem
? ? ?
Activity D, however, again requires you to exercise common sense. D must be done (LF) so that both F and the dummy get started on time (LS). Since F must start at 12 and no later, which is earlier than the dummy must start, D must done so that F can start on time. On the backwards pass, you take the SMALLER of the Latest Start times for the predecessor?s Latest Finish time.
5 A 0 1 6 0 B 6 6 12 5 4 C 12 9 3 9 12 E 5 14 17 1712 5 14 17 G 3 8 2 5 5 5 D 7 12 12 4 1712 12 12 8 F 20 20 17 20
6
Time Management problem
?
We are down to calculating the Latest Finish and Latest Start for activity A. Once again, we must consider two followers: C and D. C must be started at time 8 and D must be started at time 5. Since D is more urgent, A copies the smaller of the LS times and has a Latest Finish time of 5. This is shown in the completed network:
5 A 0 1 6 5 0 0 B 6 6 12 4 C 12 9 3 9 12 E 5 14 17 1712 5 14 17 G 3 5 2 8 5 5 5 D 7 12 12 4 1712 12 12 8 F 20 20 17 20
6
Time Management problem
?
?
? ?
First, we consider a new idea for the project: slack for each activity. SLACK is simply the difference between the earliest you can start an activity (ES) and the latest you are allowed to start the activity (LS). If these two numbers are the same, then the activity has no slack. The more slack an activity has, the less worrisome it is, because you have time to start the activity or wait, but if you start it and something goes wrong, then you have time to correct the problem and still get the activity done on time.
Time Management problem
?
? ? ?
For an activity with zero slack, though, you must start it as soon as you can and you have no time for mistakes. These are the activities that you must supervise yourself. The activities with zero slack form a string from the beginning node to the ending node. This string is called the CRITICAL PATH and the zeroslack activities are referred to as CRITICAL ACTIVITIES. If any critical activity is delayed at all, so that it does not finish on time, then all of the subsequent critical activities will start later than they should, and the entire project will be delayed.
Thank You…
?
Thank You…
Time Management Problem
?
? ? ?
Practice problem: Find out al the 4 times for all the activities What is project duration? What is critical path?
Activity A B C D E F G
Predecessors --A A B,C D D,E
Activity Time
5 3 6 2 4 7 3
Time Management problem #3
Q3) A Project Manager is using AOA to perform critical path analysis. a) Draw a network diagram for the activity, duration and dependency data provided below and find out critical path. b) What is the Float on activity B? What is Float on activity H?
c) If Activity Duration C=4 and B = 8. Discuss change in Critical path. Give definition of Critical Path, Float and Lag Discus different Activity diagramming techniques
Activity A C B D E F G H I R Duration 3 3 2 5 2 4 3 1 2 0 Dependent on None none A C none E D,F D,F B,G H,I
Thank You…
?
Thank You…
Agile Planning
?
?
?
Provides project teams with a means to produce features in a short amount of time in order to gain useful feedback from users, customers, and stakeholders. It also allows teams to defer decisions on detailed requirements until the feature is being developed, allowing them to apply the most current and accurate information possible. This approach works when the team has decided to follow an iterative and incremental project approach and is most useful in situations where the product of the project can be delivered in small increments
Project Life Cycle
Project Life Cycle Sequential Model
Planning Definition Design Implementation Integration System Test Operation
Phased (Waterfall) Model
Planning Definition Design Implementation Integration Time System Test
Shortened Interval
Earlier Time-to-Market
Operation
doc_121902744.pptx
time management and why time management is necessary, what are the main culprits of wastage of time in the project, different tools and techniques to manage time, wideband Delphi Method. It also explains critical path method.
Project Scope Management
.
What is Time Management?
What is Time Management?
Definition:
?
The Predictable control an individual can exercise over a series of events.
What is Time Management?
? Time
management is the development of processes and tools that increase time-efficiency.
Why it is necessary?
?
What does Time (Self) Management ?Do for you? ?Do for your job? ?Do for you group? ?Do for your organization?
Time Wasting Culprits
Telephone Interruptions ? Inefficient Delegation ? Extended Lunches or breaks ? Cluttered Work Space ? Poorly run meetings ? Socializing on the Job ? Misfiled information
?
Time Wasting Culprits
Poor Planning ? Procrastination (putting off or delaying or deferring an action to a later time ) ? Waiting/ Delays ? Paperwork ? Junk emails ? Drop-In visitors ? Not Setting/ Sticking to priorities
?
What is Time Management?
Processes to ensure the timely completion of the project. Major processes ? Activity definition
?
Identifying the specific activities Documenting activity dependencies Estimating time to complete individual activities Create a project schedule Controlling changes to the project schedule
? ? ? ?
Activity sequencing
?
Activity duration estimating
?
Schedule development
?
Schedule control
?
Activity Definition (Planning)
?
Activity definition involves identifying and documenting the activities that must be performed in order to produce the deliverables and sub deliverables identified in the WBS.
Activity Definition…
Inputs
WBS Scope statement Historical Information Constraints Assumptions
Tools & Techniques
Decomposition Templates
Outputs
Activity List Supporting Detail WBS Updates
Inputs
? ?
?
? ?
Work breakdown structure ? Primary input Scope statement ? Project justification and objectives must be explicitly considered. Historical information ? Activities performed in previous projects should be considered Constraints ? Factors that will limit the team’s options Assumptions ? Factors considered to be true.
Tools and Techniques
?
?
Decomposition ? Similar to the decomposition of work as part of Scope Definition. ? Activities are explored instead of deliverables. Templates ? Activity list from previous projects or activity lists of a WBS element can be useful. ? Process descriptions in the quality manual.
Output…
?
?
Activity list ? All activities which will be performed during the project or phase. ? It should be organized in relation to the WBS to ensure completeness. ? Should include descriptions of each activity. Supporting detail ? Supporting detail of the activity list including assumptions and constraints should be documented.
Activity Sequencing (Planning)
?
Activity sequencing involves identifying and documenting interactivity dependencies.
? This
has to be done accurately in order to support later development of realistic and achievable schedules. ? Sequencing can be done by project management software or manual technique. ? Manual technique could be used in small projects or in initial phases of large projects when little detail is available
Activity Sequencing (Planning)
Inputs Activity Lists Product Descriptions Mandatory Dependencies Discretionary Dependencies External Dependencies Assumptions Constraints Tools & Techniques Precedence Diagramming Method Arrow Diagramming Method Conditional Diagramming Method Network Templates Outputs Project Network Diagram Activity List Updates
Inputs
? ?
Activity list
? Created
as an output of activity definition characteristics may affect activity sequencing.
Product description
? Product
?
Subsystem modules should be coded before integration test can be performed
? Should
be reviewed to ensure accuracy. in the nature of the work being done.
?
Mandatory dependencies
? Inherent
?
Baseline of a package is created after all the modules are unit tested.
Inputs
?
Discretionary dependencies – preferred logic
? Dependencies defined by the project management. ? Might be based on best practices or exceptional
cases.
?
Modules can be reviewed before compiled to improve productivity.
?
External dependencies
? Dependencies
involve relationships with non-project
activities.
?
Keyboard is required before testing the keyboard driver. Assuming the project objective is to build the driver only)
?
Milestones
? Milestone
events should be part of the activity sequencing
Tools and Techniques
?
Precedence diagramming method (PDM) – Activityon- node
? Nodes represent activities ? Arrows represent dependencies – precedence relationships ? Finish to start – from activity must finish before the to
activity can start
? Finish
to finish – from activity must finish before the to activity can finish
? Start
to start – from activity must start before the to activity can start
to finish – from activity must start before the to activity can finish
?
? Start
Can you think of an example?
PDM Network Chart
Tools and Techniques
?
Arrow diagramming method – Activity-onarrow
? Arrows
represent the activities ? Nodes represents events ? Only finish-to-start dependency is represented
Events versus Activities
?
Event = a point in time
? has
no duration ? e.g the start or end of an activity
?
Activity = a task or an action with a recognizable start and finish and a duration
Tools and Techniques
?
Conditional diagramming methods
? Allow
?
non-sequential activities such as loops or conditional branches.
?
Acceptance test that must be repeated until product is acceptable Design update task is required only if the review requires revision.
? System
Dynamics Modeling ? Control Flow Diagrams
?
Network templates
? Standardized networks can be used … ? For entire or part of the project ? Portions of a network are called subnets
Outputs
?
Project network diagram
? Depicts
?
the project`s activities and dependencies among activities.
Project Network Diagram is NOT a PERT chart. ? PERT technique relates solely to time scales and virtually identical to CPM.
?
Activity list updates
? Preparation
?
of the network diagram may clarify the need
For more detailed activities ? To redefine activities
Activity Duration Estimating (Planning)
?
Estimating the time required to complete each required activity. ? Activity duration estimating involves assessing the number of work periods likely required to complete identified activity. ? The person or group who is most familiar with the nature of specific activity should make or at least approve the estimate. ? While making the activity duration estimate one needs to take into consideration the elapsed time as well.
Activity Duration Estimating (Planning)
Inputs Activity List Assumptions Constraints Resource requirement Resource capability Historical Information Tools & Techniques Expert Judgment Analogous Estimation Simulation Outputs Activity Duration Estimates Basis of Estimates Activity List updates
Inputs
? ? ? ?
Activity list Constraints Assumptions Resource requirements
? Duration
?
of activities are usually related with the resources assigned to them.
?
Coding of a 100 LOC class can be performed by 1 programmer in one day By 2 programmer in two days!
?
Resource capabilities
? The
?
duration of activities are also related with the capability of the resources
Productivity of programmers has the ration 1:10
Inputs
?
Historical information
? Project
?
files
Contain information related with estimation of activities at team, individual levels.
? Commercial
?
duration estimating databases
Software cost/effort/duration estimation tools usually based on and include data on significant number of projects
? ? ? ?
COCOMO COPMO SLIM Knowledge Plan
? Project
?
team knowledge
Although not very reliable could be the only source of information for many software projects.
Tools and Techniques
?
Expert Judgment ?Expert judgment guided by historical information is frequently the only possibility. ?A structured approach to minimize judgment errors is called Wideband Delphi method
Wideband Delphi Method
?
Several experts individually produce estimates then those estimates converge on a consensus estimate. ? 1. A group of experts given source documents and estimation form ? 2. Meeting 1: discuss project goals, assumptions, estimation issues ? 3. Each anonymously list tasks and estimated sizes ? 4. Estimates are tabulated by a moderator and given back to experts. Personal estimate is identified others anonymous. 0 20 40 60 80 100 X X* X! X X X*= Your Estimate, X!=Median Estimate ? 5. Meeting 2: discuss results ? Bring insight to the problem ? 6. If possible, reach a consensus estimate ? If no consensus, break until you can gather additional data, then goto step 3
Tools and Techniques
?
Analogous estimating – top-down
? Using
?
the actual duration or effort of a previous similar activity as the basis.
Suitable for early phases ? Similarity of activities should be high ? Individuals can calibrate the results
?
Quantitatively based durations – bottom-up
? Activity
effort = Quantity * Productivity
Output – Activity Duration Est.
Activity duration estimates ?Should always include the range of possible results. ? Basis of estimates ?Assumptions made in developing the estimate ? Activity list updates
?
Top-Down Software Estimation Models
COnstructive COst MOdel
63 TRW projects size range from 2,000 SLOC to 966,000 SLOC ? Heterogeneous: Incorporates different application domains. ? There are three COCOMO levels
? Basic ? Intermediate (the most popular) ? Detailed
?
?
The different versions of the model represent different levels of detail or precision
Problems with CoCoMo
?
?
?
? ?
Ignores customer attributes ? Skill, Cooperation, Knowledge, Responsiveness ? “You cannot have a level 3 organization with a level 1 customer.” Oversimplifies the impact of security issues Ignores software safety issues Ignores SW development environment Ignores personnel turnover levels
CoCoMo Works Well
?
COCOMO works well
? If
you feed actual data from many real programs,
? ?
you can often find a set of Cocomo constants and adjustment factors that fit your organization well sometimes you need to add unique adjustment factors associated with your organization
?
?
?
COCOMO is a simple, exponential curve fit algorithm -- many situations can be fitted to exponential curves As long as new projects are not dramatically different in size, complexity, or process, COCOMO can be quite valuable as an estimating tool Better not to rely on just one estimation model
Bottom-up Estimation
?
Effort = Size / Productivity ?Size can be represented by Function Points ?Productivity can be defined as FP / Person-Months
Schedule Development (Planning)
?
Schedule development means determining the start and finish dates for project activities. ? These have to be realistic for the project to finish on schedule. ? Schedule development process have to iterated with the required inputs from the different process prior to the development of schedule
Schedule Development
Inputs Tools & Techniques Outputs
Project Network Diagram
Activity Duration Estimates
Mathematical Analysis
Schedule Compression
Project Schedule
Supporting Detail
Resource Requirement
Resource Pool Description Calendars
Simulation
Resource Leveling Project Management Software
Schedule Mgmt Plan
Resource Requirement Updates
Leads & Lags Constraints Assumptions
Inputs
? ? ? ?
Project network diagram Activity duration estimates Resource requirements Resource pool descriptions
? Knowledge of availability ? what resources, ? when, ? in which pattern.
of
?
Calendars.
? Identification of periods when work is allowed ? Project calendars – effect all resources ? Resource calendars – effect specific resources
Inputs
?
Constraints
? Imposed
dates ? Key events or major milestones
Assumptions ? Leeds and lags
?
? Activity
dependencies may require lead or lag specifications ? Completion of a training and application of a tool might require to specify 2 day lag.
Tools and Techniques
?
Mathematical analysis
? Calculating
early and late start and finish dates for all project activities with no resource constraints. ? The results are not the schedule but indications of scheduled dates. ? Critical path method (CPM)
?
?
?
?
Calculate early and late start and finish date for each activity, based on sequential network logic and single duration estimate Focus is to determine activities which has the least schedule flexibility.
Start and Finish Times
Earliest start (ES) ? Earliest finish (EF) = ES + duration ? Latest finish (LF) = latest task can be completed without affecting project end ? Latest start = LF - duration
?
Critical Path Method
Forward pass: ? Initial conditions for the first activity
?
? EST
=0 ? EFT = EST + Duration
?
For all subsequent activities
? EST
= maximum EFT of preceding activities ? EFT = EST + duration
Critical Path Method
?
?
?
Backward pass: Terminal condition for the last activities: ? LFT = EFT ? LST = LFT - duration For all previous activities: ? LFT = minimum LST of following activitie ? LST = LFT - duration
Float
Float = Latest finish - Earliest start – Duration ? Any activity with the float 0 is critical
?
Tools and Techniques
?
?
Program evaluation and review technique (PERT) ? Calculate project duration based on ? sequential network logic and ? weighted average duration estimate It uses distribution?s mean instead of the most likely estimate.
Tools and Techniques
Tools and Techniques
?
? ?
Duration compression ? Looking for ways to shorten the project schedule without changing the scope. ? Crashing ? By analyzing cost and schedule trade-offs determine greatest compression for minimum cost. ? Fast tracking – co-engineering ? Doing activities in parallel that would normally be done sequentially. Simulation Resource leveling heuristics ? Mathematical analysis does not necessarily produces a manageable schedule. ? Heuristics can be used to level resources ? „allocate scarce resources to critical path activities first?
Tools and Techniques
?
Project management software
? Automate
the calculation of mathematical analysis and resource leveling. ? Enables what-if analysis ? Very flexible to report project schedule
Output
?
Project schedule
? Includes
at least planned start and expected finish dates. ? Project schedule considered preliminary till confirmed resource assignments. ? Project schedule representation
Project network diagrams ? Gantt charts – milestone charts ? Time scaled network diagram
?
Project Network Diagram
Gantt Diagram
Output
?
Supporting detail
? All
identified assumptions and constraints are included ? Resource – human resource - requirements by time period ? Alternative schedules ? Schedule risk assessment
?
Schedule management plan
? Defined
how changes to the schedule will be managed. have significant effect on preliminary estimates
?
Resource requirement updates
? May
Schedule Control
?
Schedule change control is concerned with ?Influencing the factors which create the Schedule changes to ensure that they are beneficial ?Determining that the Schedule change has occurred ?Managing the Schedule changes when they actually occur
Schedule Control
Inputs Project Schedule Performance Reports Change Requests Schedule Management Plan Tools & Techniques Schedule Change Control System Performance Reports Additional Planning PM Software Outputs Schedule Changes Corrective Actions Lessons Learned
Inputs
?
Project schedule
? The
schedule baseline, is a component of the overall project plan. ? It provides the basis for measuring and reporting schedule performance.
?
Performance reports
? Provide information on schedule performance ? which planned dates have been met and which have not.
?
Change requests
? May
occur in many forms ? Changes may require extending the schedule or may allow accelerating it.
?
Schedule management plan
Tools and Techniques
?
Schedule change control system.
? Defines
the procedures by which the project schedule may be changed. ? It includes the paperwork, tracking systems, and approval levels necessary for authorizing changes. ? Schedule change control should be integrated with the overall change control system
?
Performance measurement.
? Performance
measurement techniques help to assess the magnitude of any variations ? Enables to decide if the schedule variation requires corrective action.
?
For example, a short delay on a critical or near-critical activity may require immediate action.
Tools and Techniques
?
Additional planning
? Changes
may require new or revised activity duration estimates, modified activity sequences, or analysis of alternative schedules.
management software enables
?
Project management software.
? Project
?
tracking planned dates versus actual dates and ? forecasting the effects of schedule changes
Outputs
?
Schedule updates
? Schedule
updates may require adjustments to other aspects of the overall project plan. ? Revisions are changes to the scheduled start and finish dates in the approved project schedule. ? Schedule delays may be so severe that “rebaselining” might be needed.
?
Corrective action.
? Often involves expediting. ? Special actions taken to ensure
completion of an activity on time or with the least possible delay. causes of variances, the reasoning of corrective actions etc., should be documented
?
Lessons learned.
? The
Time Management Problem
?
Thank You…
Time Management Problem
?
? ?
How to draw a project management network for the activity and predecessor information provided. First, remember the two questions you want to answer: When will the project be done, and Which activities will require our personal attention
Activity
Predecessors
A
B C D E F G
--A A B,C D D,E
Time Management Problem
?
With this information, we were able to draw the network as given below:
2 A D 4 F
1 B 3
C G E
6
5
Time Management Problem
?
?
?
? ?
Our next step is to collect the data that will tell us how long each activity will take. For CPM, this is a single number, called the NORMAL activity time. For PERT, you get three numbers, an OPTIMISTIC, a PESSIMISTIC, and a MOST LIKELY. These three are averaged together to get a single EXPECTED activity time. Whether you are using PERT or CPM, you end up with a single number to use and you use them the same way.
Time Management Problem
?
?
Whether you are using PERT or CPM, you end up with a single number to use and you use them the same way. For this example, the activity times are:
Activity A B C D E F G
Predecessors --A A B,C D D,E
Activity Time
5 6 4 7 5 8 3
Time Management Problem
We will use this information and the network we have drawn to calculate four numbers for each activity. These are: ? ES = the EARLIEST START time, or the earliest time the activity can start, allowing for all predecessor activities to finish. ? EF = the EARLIEST FINISH time, or the ES plus the ACTIVITY TIME. ? LF = the LATEST FINISH time, or latest time the activity can finish if all subsequent activity are to be started and finished on time. ? LS =the LATEST START time, or the LF minus the ACTIVITY TIME.
Time Management Problem
?
All of these numbers will be recorded on the network. The figure shown next is a key for interpreting the network , showing where each number should be placed.
Earliest Start Latest Start Activity Name Activity Time Earliest Finish Latest Finish
Time Management Problem
?
Now, using the key, the data given, and the network, we can begin to answer our questions. First, for each activity, enter the activity times you were given into the network, underneath the arrow, in the center:
2 A 5 1 B 6 3 E 5 5 4 C G 3 D 7 F 8 6 4
Time Management Problem
? ? ?
?
The DUMMY activity (the dotted line from node 4 to node 5) has no activity time, because it takes no time to complete. The DUMMY, remember, is simply used to show the precedence relationship of D before G. The next step is to complete a FORWARD PASS through the calculations. This means to start on the left, at node 1, and calculate the Early Start and Early Finish time for each activity. Since activities A and B have no predecessors, they can begin right away, so the ES is set equal to zero. As noted before, the Early Finish time is simply the activity?s Early Start plus the activity time written below the activity arrow.
5 A 0 1 0 B 6 6 3 E 5 5 5 4 C G 3 2 D 7 F 8 6 4
Time Management Problem
? ? ? ?
For example, A is the predecessor to D, so A must be finished before D can begin. Since the earliest finish for A is 5, then the earliest D can begin is 5. The same is true for C; the earliest C can begin is 5, because that is the earliest A can finish. However, we cannot determine the earliest start for E, because B and C must be completed, and we do not have the earliest finish for C shown on the network. The only two activities we can calculate are C and D, so we add the ES and EF for those two to the network:
5 A 0 1 0 B 6 6 5
2 5
5
D 7
12
4 F 8
4 C 9 3 E 5 5 G 3
6
Time Management Problem
? ? ?
Let us calculate ES and EF for remaining activities. F is rather simple, having only one predecessor - activity D - activity F can begin as soon as activity D is done, so the Early Start time for F is the same as the Early Finish time for D, or 12. The Early Start time for activity E requires a little common sense. B and C are the predecessors, so BOTH B and C must be done before E can begin. Therefore, take the larger of the Early Finish times for B and C, then record that as the Early Start time for E. For E, F, and the dummy, the EF time is calculated as before, by adding the activity time to the ES. This gives us:
5 A 0 1 0 B 6 6 3 9 E 5 14 5 5 4 C 9 12 G 3 2 5 5 D 7 12 8 F 20 6 12 4 12
Time Management Problem
?
?
ES and EF for the dummy are the same. This is because the dummy takes no time. The only reason for showing the ES and EF for the dummy is to make it easier to calculate the Earliest Start time for G. Since all the predecessors for G (E and D, through the dummy) have their earliest finish times shown, we compare their EF times (12 and 14) and select the largest as the earliest start time for G.
5 A 0 1 0 B 6 6 3 9 E 5 14 5 5 4 C 9 12 14 G 3 2 5 5 D 7 12 8 F 20 6 17 12 4 12
Time Management problem
? ?
? ?
Since F and G are final activities, we will be done at the later of their Early Finish times, which is 20. With this information, we can begin a BACKWARDS PASS through the network, calculating the Latest Finish and Latest Start times for each activity, beginning on the right with activities F and G, and moving to the left. If we are going to promise to have the project done at time 20, then clearly the Latest Finish we can allow for either of the final activities is 20. To get the Latest Start for any activity, simply SUBTRACT the activity time from the Latest Finish time.
5 A 0 1 0 B 6 6 3 9 E 5 14 5 5 4 C 9 12 14 17 G 3 2 5 5 D 7 12 12 4 12 12 8 F 20 20 17 20
6
Time Management problem
? ?
?
The backwards pass is a little trickier than the forward pass because you have to think about both predecessors and followers, but the logic is very similar. For example, both E and the dummy (representing D) must be done so that G can begin on time. Therefore, the Latest Finish for E and the dummy is the same as the Latest Start time for G. We cannot, however, determine the Latest Finish time for D, because both F and the dummy follow D and we have not yet shown the Latest Start time for the dummy. So, we next fill in the LF and LS for E and the dummy:
5 A 0 1 0 B 6 6 3 9 12 E 5 14 17 5 5 4 C 9 1712 14 17 G 3 2 5 5 D 7 1712 12 4 12 12 8 F 20 20 17 20
6
Time Management problem
? ? ?
Activity D, however, again requires you to exercise common sense. D must be done (LF) so that both F and the dummy get started on time (LS). Since F must start at 12 and no later, which is earlier than the dummy must start, D must done so that F can start on time. On the backwards pass, you take the SMALLER of the Latest Start times for the predecessor?s Latest Finish time.
5 A 0 1 6 0 B 6 6 12 5 4 C 12 9 3 9 12 E 5 14 17 1712 5 14 17 G 3 8 2 5 5 5 D 7 12 12 4 1712 12 12 8 F 20 20 17 20
6
Time Management problem
?
We are down to calculating the Latest Finish and Latest Start for activity A. Once again, we must consider two followers: C and D. C must be started at time 8 and D must be started at time 5. Since D is more urgent, A copies the smaller of the LS times and has a Latest Finish time of 5. This is shown in the completed network:
5 A 0 1 6 5 0 0 B 6 6 12 4 C 12 9 3 9 12 E 5 14 17 1712 5 14 17 G 3 5 2 8 5 5 5 D 7 12 12 4 1712 12 12 8 F 20 20 17 20
6
Time Management problem
?
?
? ?
First, we consider a new idea for the project: slack for each activity. SLACK is simply the difference between the earliest you can start an activity (ES) and the latest you are allowed to start the activity (LS). If these two numbers are the same, then the activity has no slack. The more slack an activity has, the less worrisome it is, because you have time to start the activity or wait, but if you start it and something goes wrong, then you have time to correct the problem and still get the activity done on time.
Time Management problem
?
? ? ?
For an activity with zero slack, though, you must start it as soon as you can and you have no time for mistakes. These are the activities that you must supervise yourself. The activities with zero slack form a string from the beginning node to the ending node. This string is called the CRITICAL PATH and the zeroslack activities are referred to as CRITICAL ACTIVITIES. If any critical activity is delayed at all, so that it does not finish on time, then all of the subsequent critical activities will start later than they should, and the entire project will be delayed.
Thank You…
?
Thank You…
Time Management Problem
?
? ? ?
Practice problem: Find out al the 4 times for all the activities What is project duration? What is critical path?
Activity A B C D E F G
Predecessors --A A B,C D D,E
Activity Time
5 3 6 2 4 7 3
Time Management problem #3
Q3) A Project Manager is using AOA to perform critical path analysis. a) Draw a network diagram for the activity, duration and dependency data provided below and find out critical path. b) What is the Float on activity B? What is Float on activity H?
c) If Activity Duration C=4 and B = 8. Discuss change in Critical path. Give definition of Critical Path, Float and Lag Discus different Activity diagramming techniques
Activity A C B D E F G H I R Duration 3 3 2 5 2 4 3 1 2 0 Dependent on None none A C none E D,F D,F B,G H,I
Thank You…
?
Thank You…
Agile Planning
?
?
?
Provides project teams with a means to produce features in a short amount of time in order to gain useful feedback from users, customers, and stakeholders. It also allows teams to defer decisions on detailed requirements until the feature is being developed, allowing them to apply the most current and accurate information possible. This approach works when the team has decided to follow an iterative and incremental project approach and is most useful in situations where the product of the project can be delivered in small increments
Project Life Cycle
Project Life Cycle Sequential Model
Planning Definition Design Implementation Integration System Test Operation
Phased (Waterfall) Model
Planning Definition Design Implementation Integration Time System Test
Shortened Interval
Earlier Time-to-Market
Operation
doc_121902744.pptx