Project Management: Probabilistic Scheduling and Critical Chain Theory

This document discusses the concepts of probabilistic scheduling and critical chain theory in project management. It explores the importance of accurate time estimation, resource allocation, and project scope management. The document also highlights the causes of project delays and provides insights on how to minimize them.

Project Management

Contents
Introduction:...............................................................................................................................2
Answer 1....................................................................................................................................2
Probabilistic scheduling:........................................................................................................2
Comparison between PERT chart and Monte-carlo simulation:............................................3
Answer 2:...................................................................................................................................4
Answer 3:...................................................................................................................................6
Answer 4:...................................................................................................................................8
Objectives of project scope management plan.......................................................................8
Benefits of Project scope management plan:.........................................................................9
Answer 5:.................................................................................................................................10
Critical path of project.........................................................................................................10
Planned duration of project in Weeks..................................................................................11
Identify non-critical tasks and float value for each activity.................................................11
References................................................................................................................................13

Introduction:
In the given case study, the project fails due to unclear estimation of time duration for
completing the tasks flawlessly. Productivity of the workers gets affected due to insufficient
time allocated to them. Failure of the project occurs since ineffective project planning
methodology is applied which hinders the accuracy in the estimation of time. Overrunning of
the project occurs by not assuming uncertainties associated with project development plan to
synchronise time and budget to achieve common goal and objectives (Ollows, 2015).
Problem solving approach helps in managing team spirit and improve the quality of work
provided by the worker and helps in completing the project with accuracy.
During the investigation, it is identified that deterministic schedules are prepared for
managing the interconnection between the tasks to describe interdependencies to improving
the performance of work and with expected duration of work. Planning of task is based on
allocation of resources and time duration to complete the work within the given time
framework (Tomomitsu, Carvalho, and Moraes, 2018). Predecessor and successor of the
tasks are allocated with each activity to clarify the dependencies of task. Closed network of
activities is created which helps in defining the critical path of the project plan. Effective
action for minimizing the impact of critical path and completing the activities within the
given time helps in lowers down the risks and complexities associated with it.
Answer 1
Probabilistic scheduling:
In probabilistic scheduling, network of activities is managed by inducing the random
variables to the activities for allocation of time. Starting and end date of the project is
specified. There is no fixed value of time duration for completing activities. Activities are
completed at random time variables. Activities of probabilistic scheduling are same as
deterministic scheduling such as synchronising activities, allocation of cost, allocation of
time, allocation of resources (Sulaman, Weyns, and Host, 2013).
The two commonly used probabilistic scheduling are pert chart and monte-carlo simulation.
Pert Chart
Pert chart are developed for allocating the duration of time. Estimation of activities depends
on pessimistic and optimistic value to the project schedule and tasks.

Variability of project activities can be measured by adding the variance of time associated
with each activity (Ryan, and Efatmaneshnik, 2015). Probability can be determined by
defining the pert analysis. Key activities of probabilistic scheduling are highlighted below:
 No fixed value of time duration for completing activities
 Major activities are synchronising activities, allocation of cost, allocation of time,
allocation of resources
 Pert chart are developed for allocating the duration of time
Monte-carlo simulation:
Monte-carlo simulation is the mathematical approach which is used for evaluating the risks
and uncertainty associated with the accessing of information. Decisions are depends on the
analysis of risks impact on the project outcome. Quantitative risks analysis helps in
increasing the efficiency and effectiveness of the decision making process. It is based on
probability distribution which are named as normal, Lognormal, uniform, and triangular. It
provides graphical results of the processes and helps in evaluating the scenario and sensitivity
analysis.
Comparison between PERT chart and Monte-carlo simulation:
PERT chart Monte-carlo Simulation
In Pert chart, network of activities is
managed by inducing the random variables to
the activities for allocation of time.
Monte-carlo simulation is the mathematical
approach which is used for evaluating the
risks and uncertainty associated with the
accessing of information (Obradovic, and
et.al., 2014).
Certainty of time duration for completing the
given tasks is not fixed
Duration of activities is allocated by
analysing the details of quantitative data
It focuses on research and development
program for completing the tasks with
efficiency and expertise
It focuses on evaluating the risks associated
with the project activities
It does not focus on the project failure and
factors responsible to hinder the successful
completion of project
It focuses on the project failure and factors
responsible to hinder the successful
completion of project. It helps in minimizing
the risks at an early stage of the project for

the smooth functioning of the project
Research and development program is
arranged for completing the task
Historical data analysis is carried on finishing
the tasks.
Data is collected during the project Data is collected at the project initiation
phase
Answer 2:
Rescheduling of the project occurs due to the underestimation of cost. Development of the
project budget is the most crucial part of the project which is normally ignored by the project
manager which affects the quality of the project at the completion project development plan.
Wrong estimation of the project budget is not a good planning technique to emphasis better
coordination between the project processes. Overrunning of cost occurs due to the ignorance
to the critical chain of activities to finish the task with excellence. Complexity of the project
increases by attaching inaccurate cost to the activity schedule. Probability of risks occurrence
gets increased by analysing the critical path activities (Mossalam, and Arafa, 2016).
Overrunning of cost directly affects the completion of project within the dedicated deadline
because it affects the availability of resources which had a direct impact on the capabilities
and performance of the workers indulges in finishing the tasks. Increasing cost of the
activities accelerates the project budget approved in the project initiation phase. There is a
direct relationship between times and cost constraints which are associated with the project
management. Increment in the project cost increases the time required to finish the tasks
within the given time domain (Hamad, 2018). Statistical approach should be used for
managing the balance between the two constraints so that project can be completed without
any delay. Volatile environment of the project can be controlled by bringing accuracy in the
allocation of time and cost. Reliable and realistic approach can be scheduled to the project
activities by deploying the agile project management methodologies.
Goldratt critical chain theory is used for minimizing the probability of critical path
occurrence in the project development life cycle. The focus is given on minimizing the gaps
which exist between early start and late finish of the project planned activities. In the
traditional working project management technique, completion of activities is lie between
four dates which are named as early start, early finish, late start, and late finish. Buffer time
of the activities get increased (Haron, and et.al., 2013). Goldratt theory says that project
schedule should be prepared on the basis of buffered time associated with each activities. It

helps in calculating the slack value or float value so that complexities associated with the
activities completion time can be minimised. Emphasis is given on evaluating the critical path
of the undertaken project which helps in defining the critical activities. Preference is given to
solve critical activities at top priority before the completion of non-critical activities.
Goldratt terminology emphasised on the following:
 Development of the project schedule by evaluating the occurrence of critical activities
and non-critical activities.
 Critical chain of activities helps in defining the critical path of the project.
 Longest path of the project schedule is known as critical path
 Critical activities are to be solved at top priority
 Evaluating float value associated with each activity
 Activity which are having zero float value are come under critical activities
 Activity which are having non-zero float value are come under non-critical activities
 Non-critical activities chain is called as Feeder chain
 Development of critical chain and feeder chain helps in evaluating the risks associated
with the project plan
 Project schedule should be prepared on the basis of buffered time associated with
each activity (Haughey, 2014)
 Conflict associated with the resource distribution plan can be minimized by managing
the accuracy in determining the critical chain and feeder chain
 Critical chain activities are not affected by the buffer associated with the non-critical
activities
 It helps in completing the 95% of the project successfully.
 Volatile environment of the project can be controlled by bringing accuracy in the
allocation of time and cost.
 Reliable and realistic approach can be scheduled to the project activities
 minimizing the gaps which exist between early start and late finish of the project
planned activities
Critical chain methods helps in minimizing the rescheduling of the project which directly
affects the project budget and the time allocated to finish the task. Goldratt investigation says
that root cause of the project failure is to ignore the critical activities associated with the
project plan because it affects the distribution of resources which directly affects the project
cost and completion time of the project (Kumar, and Bansal, 2010). Emphasis is given on

establishing the dependencies between the tasks so that right operations can be performed at
right time. Conflict associated with the resource distribution plan can be minimized by
managing the accuracy in determining the critical chain and feeder chain. Acceleration of the
activities can be done by synchronising and aligning the task in accordance with the certainty
of tasks (Badewi, 2015). Marginal duration of time should be given to the activities so that
smooth operations can be performed. It is recommended to analyse and evaluate critical flow
of activities at glance so that buffer time associated with the task completion can be
manageable and helps in completing the tasks within the given time frame and cost. Success
of the project depends on the alignment of critical activities chain and non-critical activities
chain to evaluate the buffer time associated with the complete phase of the project
development cycle.
Answer 3:
Contingencies of the project are depending on evaluating allocation of resources, work
distribution, and alignment of activities in a systematic order. From the case study, it is
analysed that failure of the project completion occurs due to Parkinsons law and student
syndrome. Parkinsons law states that the original time required to complete the given tasks is
more than the estimated and assignment duration due to the difference in the contribution of
the workers and their capabilities. Student syndrome states that dependency of one activity
over the other affects the completion of project within the dedicated deadline. One activity
has to be waiting for the other to complete.
Some of the major causes for the project delay than the scheduled time are highlighted below:
 Time: Activities are dedicated with the acquired deadline. Allocation of time duration
without any research and development and historical analysis results in project delay
because the team members are not able to complete their tasks within the given
timeframe. Productivity of the workers gets affected due to insufficient time allocated
to them. Failure of the project occurs since ineffective project planning methodology
is applied which hinders the accuracy in the estimation of time.
 Dependency: Project manager is responsible for establishing dependency, successor,
and predecessor of activities. Expertise and creative skills of the project manager
plays a key role in establishing dependency between the activities. Delay in
completion of one activity will directly affects the completion time taken by the other

activities and results in exceeding the time limit for project delivery. Appointment of
unexperienced project manager creates the problem of process alignment and
dependency of tasks. Emphasis is not given on establishing the dependencies between
the tasks so that no right operations can be performed at right time. Predecessor and
successor of the activities results in no proper distribution of resources and team
member performance get affected. They are not able to complete the tasks on time.
 Inaccuracy in cost estimation program: Overrunning of cost occurs due to the
ignorance to the critical chain of activities to finish the task with excellence.
Complexity of the project increases by attaching inaccurate cost to the activity
schedule. Allocation of cost to complete the tasks is not identified by evaluating the
historical data and arranging research and development program for analysing market
price of the resources which results in overrunning of cost and project failure.
Underestimation of cost results in rescheduling of the project which is time
consuming process.
 Planning and control: Project is not completed on time due to incorporation of poor
planning and control methods (Saxena, 2016). Weak planning increases the
occurrence of risks and hinders the project development phases to be completed
within the deadlines allocated to the activities (Cousillas, 2010). Project execution
depends on alignment of project activities to achieve the goal and objectives.
Inconsistency in the alignment process will not be able to achieve the desired goal.
 Project Management process: Success of the project depends on the development of
clear and concise scope management plan, stakeholder engagement plan, cost
estimation plan, project schedule, and others. Improper scheduling and application of
ineffective project management process will not results with the fruitful end product.
Requirement of the project is not defined during the project initiation will affect the
planning and project management process.
 Scope management plan: During the project initiation phase, scope management plan
is developed so that proper and effective project schedule can be prepared. Unclear in-
scope activities will affect the development of project schedule which directly affect
the performance of the project team and desired goal is not achieved within time limit
(Damoah, 2015).

Answer 4:
Objectives of project scope management plan
Success of the project scope management plan depends on the clear and concise written
agreement of stakeholder engagement plan because the completion of the project successfully
depends on the working capability, willingness, and contribution of the stakeholders
(Taherdoost, and Keshavarzsaleh, 2016). Development of the scope management at an early
stage of the project helps in defining clear role and objectives of the project, controlling the
project schedule within the optimum time, determining the work breakdown structure for
synchronising the flow of work to achieve goal within the given time frame (Anderson,
2015). Project scope gives the details of project deliverables which are provided to the end
users at the completion of the project plan. Accomplishment of work successfully depends on
the resource distribution management and expertise skills of the stakeholders. Roles and
responsibilities are defined to the stakeholders during the project initiation phase to avoid
conflict and chaos during the development phases of the project (Carcano, and et.al., 2016).
Objectives of the project scope management are:
 Determining the deliverables of the project
 Increasing communication between the team members
 Identifying risks at an early stage of the project
 Clear and concise written agreement of stakeholder engagement plan
 Identifying the working capability, willingness, and contribution of the stakeholders
 Distribution of resources according to the responsibilities given to the team members
to achieve the goal and objectives flawlessly (Atef, Henawy, and Baset, 2015).
 Clear estimation of time and cost to avoid project failure
 Defining change requirement plan
 Analysis of the business case
 Setting project constraints
 Evaluating project dependencies
 Identifying success criteria and assumptions associated with the project
 Redesigning of tasks for incorporating required changes
 Clear estimation of budget

Benefits of Project scope management plan:
Development of the project scope management is beneficial for the success of completion of
the project. Planning process of the project depends on the development of good and concise
project scope management plan. It helps in identifying the boundaries for activities to give
demonstration of in-scope and out-of-scope activities (Yadav, 2014). Project scope
management plan helps in defining following in clear and concise format for the smooth and
flawless functioning of the project:
 Project Goal and mission: Outlining of the project goal helps in determining the
sequence of activities which will be developed to flourish the desired goal
effortlessly. Core objectives of the project are identified at the start-up phase of the
project. Dependencies and assumption of the project activities is evaluated according
to the project schedule developed for completing the given mission within time frame
and cost.
 Project deliverables: End result of the project development lifecycle is expressed in
the set of project deliverables which are clearly defined during the project start-up
phase. Success measure and criteria of the project can be determined by identifying
the project deliverables efficiency in meeting the project goal (Obadia, 2018).
 Project features: Scope management plan is used for defining the operations and
functions performed by the project. It focuses on giving the details of project need and
requirement. Project charter is prepared for analysing the services and facilities
provided by the new project developed.
 Project Resources: Roles and responsibilities of the stakeholders is defined in the
project scope which have to be signed by them to avoid complicacies during the
project development phases. Distribution of resources according to the responsibilities
given to the team members to achieve the goal and objectives flawlessly.
Accomplishment of work successfully depends on the resource distribution
management and expertise skills of the stakeholders.
 Tasks determination: Sequence of activities helps in determining the allocation of
tasks to the stakeholders with required resources so that work can be completed
within the scheduled time and cost to omit the differences in project deadline and
budget proposed.
 Deadline of the activities: Historical analysis of data and operating research and
development program is helpful for allocating the duration of time required to

complete the activity without any delay. Buffer time should be given so that
completion time of the other activities is not affected.
 Cost of activities: Allocation of cost to complete the tasks is identified by evaluating
the historical data and arranging research and development program for analysing
market price of the resources. It helps in developing accurate budget of the project
and completes the project under the scheduled budget.
Answer 5:
Critical path of project
Task Name Duration Start Finish Predecessors
Management Plan 75 days Wed 11-09-19 Tue 24-12-19
Requirement Analysis 5 days Wed 11-09-19 Tue 17-09-19
System Design 15 days Wed 18-09-19 Tue 08-10-19 2
Programming 25 days Wed 09-10-19 Tue 12-11-19 3
Telecoms 25 days Wed 09-10-19 Tue 12-11-19 3
Hardware Installation 30 days Wed 09-10-19 Tue 19-11-19 3
Integration 10 days Wed 13-11-19 Tue 26-11-19 4,5
System Testing 10 days Wed 27-11-19 Tue 10-12-19 6,7
Training Support 5 days Wed 11-12-19 Tue 17-12-19 8
Handover and Go - Live 5 days Wed 18-12-19 Tue 24-12-19 9
The tasks A, B, C, D, F, G, H and I are in critical path

Planned duration of project in Weeks
Planned duration of the project is 12 week. Week wise program is displayed below
Task Name Duration Start Finish Predecessors
Duration: 1 wk - 2 wks 75d Wed 11-09-19 Tue 24-12-19
Requirement Analysis 5 days Wed 11-09-19 Tue 17-09-19
Training Support 5 days Wed 11-12-19 Tue 17-12-19 8
Handover and Go - Live 5 days Wed 18-12-19 Tue 24-12-19 9
Duration: 2 wks - 3 wks 20d Wed 13-11-19 Tue 10-12-19
Integration 10 days Wed 13-11-19 Tue 26-11-19 4,5
System Testing 10 days Wed 27-11-19 Tue 10-12-19 6,7
Duration: 3 wks - 4 wks 15d Wed 18-09-19 Tue 08-10-19
System Design 15 days Wed 18-09-19 Tue 08-10-19 2
Duration: 5 wks - 6 wks 25d Wed 09-10-19 Tue 12-11-19
Programming 25 days Wed 09-10-19 Tue 12-11-19 3
Telecoms 25 days Wed 09-10-19 Tue 12-11-19 3
Duration: 6 wks - 7 wks 30d Wed 09-10-19 Tue 19-11-19
Hardware Installation 30 days Wed 09-10-19 Tue 19-11-19 3
Identify non-critical tasks and float value for each activity
Task E, “Hardware Installation” in the schedule is the The Non critical task. The free slack
available in the for the task is 5 days.

As we can see from the schedule network that the predecessors of task G “System Testing”
are Task E “Hardware Installation” and the task F “Integration”. The task G “system testing”
to be started after the task F “Integration” which is getting finished by 26 November 2019,
while task E is getting finished by 19 November 2019. Where it can be seen that the task G
predecessor is driven by task F and E both but the task E has 5 days of float. Hence, the task
E “Hardware Installation” in the schedule is the Non critical task. The free slack available in
for the task is 5 days.
Task Name Duration Start Finish Predecessors Free Slack
Management Plan 75 days Wed 11-09-19 Tue 24-12-19 0 days
Requirement
Analysis 5 days Wed 11-09-19 Tue 17-09-19 0 days
System Design 15 days Wed 18-09-19 Tue 08-10-19 2 0 days
Programming 25 days Wed 09-10-19 Tue 12-11-19 3 0 days
Telecoms 25 days Wed 09-10-19 Tue 12-11-19 3 0 days
Hardware Installation 30 days Wed 09-10-19 Tue 19-11-19 3 5 days
Integration 10 days Wed 13-11-19 Tue 26-11-19 4,5 0 days
System Testing 10 days Wed 27-11-19 Tue 10-12-19 6,7 0 days
Training Support 5 days Wed 11-12-19 Tue 17-12-19 8 0 days
Handover and Go -
Live 5 days Wed 18-12-19 Tue 24-12-19 9 0 days
Non-critical activities with respective slack value associated with each activity is highlighted
below in the screenshot:
The free slack available in for the task is 5 days.

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