W7__Hamda__ Monte Carlo
simulation for identified Risks during
monthly invoice processing and payment) __
1-
Problem
Definition
Under
Clients Contract & Interface department there are several number of tasks
that some of them must be done in monthly basis according to certain clause in
the purchase agreement. One of these tasks is processing the monthly invoice
which is submitted in monthly basis from the project company (which is known as
a Generator) to the Buyer. Processing the monthly invoices can be considered as
a small project under CCI department since it has START and FINISH Date to be
completed. The Generator in each month (Belling period) shall submit an Invoice
to the Buyer which describes the different charges according to its product
(Power/Water). At the date of receiving the invoice, the Contract team shall
start processing the invoice and on or before the Due Date the buyer
shall pay all the payments to the Generator. If the payment is not payed to the
Generator by the Due Date, this will cause a Risk on the Buyer. W7 blog
will discuss the analysis and identifying Risk level of completing that project
by using Monte Carlo Simulation technique.
2-
Identify
the Feasible Alternative
The Monte Carlo simulation was invented by an atomic nuclear
scientist named Stanislaw Ulam in 1940, and it was named Monte Carlo after the
town in Monaco which is famous for its casinos. This is a mathematical
technique that allows to account for risks in any decision-making process. With
the help of this technique, the impact of the identified risks can be
determined by running simulations many times, and a range of possible outcomes
in different scenarios can be identified.
In order to perform the Monte Carlo simulations, it is important
to determine the schedule and we must have the duration estimate for each
activity under that project.
3-
Development
of the outcome of Alternative
Regarding to the above description of one
main task/project under CCI department, the completion of it depends on
different tasks such as:
Task 1: The submitting and receiving
Power and Water Outage Confirmations.
Task 2: Availability of the all data
required in processing the invoice.
Task 3: The preparation, editing, and
reviewing the sheet of calculations.
Task 4: The process of checking the
accuracy of such data received from the Generation.
Task 5: The process of the plant
model (FDM model).
Task 6: Finalizing the process of
monthly invoice.
Task 7: Reviewing the invoice by the
Senior Engineers and approve it.
Task 8: Reviewing the invoice by the
Department Manager and approve it.
Task 9: Reviewing the invoice by the
Department Director and approve it.
Task 10: Submitting the invoice to
Finance Department (FINISH Date).
From all these tasks, I think the
main important tasks that processing the Monthly Invoice depends on are the
first 4 one (tasks from 3-6), Because completing these four tasks on time which
make the other 4 tasks on time.
Task
|
Optimistic
|
Most Likely
|
Pessimistic
|
PERT
|
3
|
2
|
3
|
5
|
3.17
|
4
|
3
|
4
|
6
|
4.17
|
5
|
4
|
5
|
6
|
5.00
|
6
|
2
|
3
|
4
|
3.00
|
Remaining tasks
|
1
|
2
|
3
|
2.00
|
Total
|
12.00
|
17.00
|
24.00
|
17.33
|
*The
calculations of PERT are by using PERT formula
From the above table and by using PERT estimate,
these activities will be finished in 17.33 days. However, in the best case, the
activities will be finished in 12 days, and in the worst case the activities
will be finished in 24 days.
4-
Selection Criteria
Now, if we run the Monte Carlo
simulation for these tasks five hundred times by using a special Monte Carlo
simulation software, it will show us results like this:
Duration
(in days)
|
Chance of
completion
|
12
|
2 %
|
13
|
8 %
|
14
|
15 %
|
15
|
23 %
|
16
|
30 %
|
17
|
45 %
|
18
|
56 %
|
19
|
60 %
|
20
|
68 %
|
21
|
75 %
|
22
|
86 %
|
23
|
95 %
|
24
|
100 %
|
Please note that the above data is for explaining purpose only, and is not taken from an actual Monte Carlo simulation test result.
5-
Analysis and comparison of the Alternative
From table 2, it is seen that:
· 2%
chance of completing the project in 12 days
· 8%
chance of completing the project in 13 days.
· 15%
chance of completing the project in 14 days.
· 23%
chance of completing the project in 15 days.
· 30%
chance of completing the project in 16 days.
· 45%
chance of completing the project in 17 days.
· 56%
chance of completing the project in 18 days.
· 60%
chance of completing the project in 19 days.
· 68%
chance of completing the project in 20 days.
· 75%
chance of completing the project in 21 days.
· 86%
chance of completing the project in 22 days.
· 95%
chance of completing the project in 23 days.
· 100%
chance of completing the project in 24 days.
So,
by having these number of possible outcomes which are coming from running the
Monte Carlo simulation, we can understand that completing that project will be
in that specific duration by that specific percentage. And based on that, we can
determine in which level and percentage the risk of not complete the project on
that specific duration and we can make a better-informed decision to deal with
that risk.
6- Selection of the preferred Alternative
By identifying the list of activities that are under each project (processing the monthly invoices and the payment of them in the specified and scheduled time), and by specifying the PERT estimates of each activity by using PERT formula, this will help in running the Monte Carlo simulation which will help in determining number of possible outcomes for different scenarios (Risk Level). Then these outcomes will help in making the better decision to deal with that risk.
7-
Performance Monitoring and the Post Evaluation of result
Identifying the Risk level of completing
any project, helps in making and determining the preferred and better decision
to deal with that risk in the first stage and avoid it in the coming stages.
Number of tools and technique can be used in determining and identifying the
level of risk, one of these tools is Monte Carlo simulation. The Monte Carlo simulation is a very important tool
and technique in the quantitative risk analysis process which helps you make
decisions based on an objective data.
References:
1- Fahad Usmani (2017), What is a Monte Carlo Simulation? Retrieved 26 December 2017, from https://pmstudycircle.com/2015/02/monte-carlo-simulation/#comment-41717
2- A Guide to
the PROJECT MANAGEMENT BODY OF KNOWLEDGE (PMBOK GUIDE), Fifth Edition. Retrieved 26 December 2017.
3- S. Kandaswamy, The basics of Monte Carlo
simulation, Retrieved 26 December 2017, from https://www.pmi.org/learning/library/monte-carlo-simulation-risk-identification-7856
Sorry Hamda but I have to REJECT your posting. Why? Because you CANNOT add up the standard deviations. You need to add up the VARIANCES for each activity then find the square root of the sum of the variances to give you the Sigma for a string of activities.
ReplyDeletePLUS you didn't tell us what P value your PERT duration represent? P50? P75? P90.
Sorry but you have a lot more work to do in this blog so I am rejecting it expecting you will REPOST a NEW W7.1__Hamda__ Monte Carlo simulation for identified Risks during monthly invoice processing and payment)
BR,
Dr. PDG, Bali Indonesia