Dummy Data – How to use the Random Functions
Using collected or known data is the best when developing Excel models, but from time to time this may not be available when you are developing your model.
This post will look at some options for setting up Dummy Data using Excels Random functions.
Variability
Real data displays a range of variability, but this variability is generally within ranges or distributions of ranges of results.
All fields type can contain variability
ie: Country, State Names and Zip/Postal Codes, Maybe large lists but are fixed
Peoples Names, Maybe a large lists but are fixed by local rules
Ages, generally less than 80, never less than 0
Dates: Rarely before 1990 or 1900 in rare cases
Lists: are fixed
Numbers: generally random or conforming to a fixed distribution or known trend
Numbers: may include integers, decimals, negatives, extremely large numbers or all combinations
In generating random lists you will need to choose if you want random data, random data within constraints or random with a distribution. The choice is really yours and should in part be based on what the data is being used for and how accurately it needs to reflect reality.
Techniques
The techniques described below are all shown with a worked example in the attached Examples File or the Excel 2003 Example
Each example is annotated below like (Example 4.). ie: Refer to Example 4 in the above example files.
Dates
Setting up Random Dates is a simple process using the Date function.
=Randbetween(StartDate,EndDate)
Dates in a Range of Years
=Randbetween(Date(2000,1,1),Date(2011,12,31))
Will give a list of Random dates between 1 Jan 2000 and 31 Dec 2011 (Example 1.)
(Thanx Mike W)
Dates in a Month
=Date(2010, 6, Randbetween(1,30)
Will give a list of Random dates between 1 June 2010 and 30 June 2010 (Example 2.)
Don’t worry that the above formula (Example 1) can actually produce a 31 Feb 2005, the Date function will happily convert that to 3 March 2005 (Example 3.)
Dates within a Date Distribution
=DATE(2011,7,NORMINV(RAND(), 0,60))
Will give a list of Random dates between approximately 1 Jan 2010 and 31 Dec 2010, with a mean of July 1 and standard deviation of 2 Months (60days) (Example 4.)
Where NORMINV(RAND(), 0,60) will return values between -180 and +180, 99.7% of the time
Text Fields
Dependant on how many items in the list you require there are 3 techniques available
Choose
For small lists of less than 6 to 10 items you can use a simple Choose function (Example 5.)
=Choose(Randbetween(1,6),”Item 1″, “Item 2”, “Item 3”, “Item 4”, “Item 5”, “Item 6”)
VLookup
Using VLookup (Example 6.)
=Vlookup(Randbetween(1,List Length), List, 2)
Index
Using Index (Example 7.)
=Index(List, Randbetween(1, Counta(List) ))
Numbers
Small Random List of Numbers
Random from a small list of numbers (Example 8.)
=Choose(Randbetween(1,6), Numb 1, Numb 2, Numb 3, Numb 4, Numb 5, Numb 6 )
Note that the numbers:
- Don’t have to be in any order,
- Can be integers, negatives or contain decimals
- Can be repeated
eg: =Choose(Randbetween(1,6), 18, 21, -19, 36.4, 18, 24)
Random Integers
Return Integers between Start and Finish (Example 9.)
=Randbetween(Start, Finish)
=Randbetween(50, 100)
Will return an Integer between 50 and 100
Random Numbers
=Rand()
Will return a random number between 0 and 1
=Round(Rand()*100, 2)
Will Return Numbers between 0 and 100 with 2 Decimal places (Example 10.)
Random Numbers Based on a Distribution
=Norminv(Rand(), Mean, SD)
Will return a random number between 0 and 1 based on a distribution of Average = Mean and Standard Deviation = SD
=Norminv(Rand(), 50, 17)
Will return a random number between 0 and 100 based on a distribution of Average = 50 and Standard Deviation = 17, (Example 11.)
Random Numbers Fitting a Trend
If your distribution has to match a trend add a Random component to the Trends equation (Example 12.)
Y=mX+c
= rand() * X + rand()*5
= rand() * A2 + rand()*5
True/False
Choose
Use Choose and Randbetween (Example 13.)
=Choose(Randbetween(1,2), True, False)
If
Use If and Rand (Example 14.)
=If(Rand()<0.5, True, False)
Combination Text and Numbers
The above techniques can be combined to make lists of Alpha Numeric Data
Say your business has a fleet of vehicles (TR=Truck, VN=Van, CAR=Car)
=Choose(Randbetween(1,3),”TR”,”VN”,”CAR”) & Text(Randbetween(1,15),”0#”)
Will randomly choose 1 of “TR”,”VN”,”CAR” and add a random number between 1 and 15 to it format with a leading 0, eg: TR05, (Example 15.)
Other Sources of Data
Random Data
There are a number of web sites where Random Data is available.
http://www.fakenamegenerator.com/order.php
http://www.generatedata.com/#generator
http://www.melissadata.com/lookups/
Open Source Data
There are a number of web sites where Open Source Data is available.
http://www.readwriteweb.com/archives/where_to_find_open_data_on_the.php
Function Used:
Rand: Returns a random number between 0 and 1.
Randbetween: Returns a random Integer between lower and upper limits. Pre Excel 2007 Randbetween was only available through installation of the Analysis Toolpak (Thanx Luke).
Norminv: Returns the inverse of the normal cumulative distribution. That is it returns the X value from a Normal Distribution that has a know Mean and Standard Deviation where the a known cumulative percentage is supplied.
Choose: Choose an item from a list of up to 254 items.
Vlookup: Lookup the matching value from a list and return a data item from another column from the same location.
Index: Retrieve an items from a defined location within a range.
Text: Displays a number as Text with a defined format.
Other Uses of Random Functions
Of course the techniques shown here don’t have to be used for setting up Dummy Data.
One area where Random numbers is used is in Monte Carlo Simulation. This has been discussed at Chandoo.org at Data Tables and Monte-Carlo Simulations in Excel a Comprehensive Guide
Techniques
The techniques described above are all shown with a worked example in the attached Examples File or the Examples File 2003 ver
Limitations in Pre Excel 2007 versions
The Excel function, Randbetween, was only introduced in Excel 2007. As such the exaples above will only work in 2007/10.
However a simple alternative is available
Randbetween(Low, High) = Low + Int(Rand()*(High-Low))+1
Randbetween(90, 100) = 90 + Int(Rand()*10)+1
Examples using this approach are shown in the 2003 Version of the Examples files above.
How have you made Dummy Data or used the Random Functions?
How have you made Dummy Data or How have you used it ?
How have you used Random Numbers in your workbooks ?
Let us know in the comments below:
28 Responses to “Team To Do Lists – Project Tracking Tools using Excel [Part 2 of 6]”
[...] & tracking a project plan using Gantt Charts Team To Do Lists - Project Tracking Tools Part 3: Preparing a project time line [upcoming] Part 4: Time sheets and Resource management [...]
the templates are great (I bought the combo).
What I'm missing is a way to have the project gantt chart and reporting with the data per resource, in such a way that I can also show the occupation per resource on an extended gantt chart.
So with hours entered per person per project or sub-activity, to show a gantt chart of how many hours/days a person spent on which project (or plans to spend).
[...] from: Team To Do Lists - Project Tracking Tools using Excel [Part 2 of 6] 25 Jun 09 | [...]
Hi Chandoo,
Funny I have a post on the value of MS project lined up which I will post when the current monster project I'm working on finishes and I get some free time!
I'm not sure this would help with any of the projects I've worked on, closing down a to do list seems like more effort than it's worth, but it might be useful for some things. I guessing it doesn't, but does the time stamp not update when you recalculate the work book?
keep up the good work!
Ross
@Ross.. Thanks for sharing your ideas... I think to do lists are a great way to keep up with project activities and ensure accountability from individual team members, when they are implemented right.
"I guessing it doesn’t, but does the time stamp not update when you recalculate the work book?"
Your guess is right. When you change the calculation mode to "iterative", excel takes care of the nittygritties and retains older values in circular references in formulas.
[...] Project Management in Excel [New Series] - Gantt Charts | To Do Lists [...]
[...] & tracking a project plan using Gantt Charts Team To Do Lists - Project Tracking Tools Project Status Reporting - Create a Timeline to display milestones Part 4: Time sheets and Resource [...]
Hi Chandoo,
The template give me lot of convenience to monitor the thing to do. It simple. Thank You
[...] & tracking a project plan using Gantt Charts Team To Do Lists - Project Tracking Tools Project Status Reporting - Create a Timeline to display milestones Part 4: Time sheets and Resource [...]
[...] make sure you have read the first 4 parts of the series - Making gantt charts [project planning], team todo lists [project tracking], project time lines chart [reporting] and Timesheets and Resource Management using Excel. Also [...]
Chandoo,
I really do not see any befit to this function in Excel unless it was somehow tied into some other chart. That is say a scheduled activities % complete is based on the to-do list.
The only way this chart would be useful is if no one was assigned none dependent task that could be done by anyone. The cases were both of these conditions are true are so few and far between it really makes this chart worthless.
@Brian... Once you have a todo list up and running, it is easy to get metrics out of it. I didnt propose it as it might look a bit too micro-management-ish.
I am able to understand what you meant by "The only way this chart would be useful is if no one was assigned none dependent task that could be done by anyone. The cases were both of these conditions are true are so few and far between it really makes this chart worthless."
Can you explain?
"Chandoo"
What I mean is this. Lets say you have 10 task which are part of one activity/WBS that is in your schedule. One there are very few cases were many people would be assigned to complete this one scheduled activity with no direction being given who should what of the 10 task. It is poor management, and the task 90% of the time would not get done in a timely manner if say 4 people were responsible. Secondly, you are assuming all 10 task are independent of each other. You might need to do task 1 thru 3 before you can do task 4, and to do task 7 you might need to do 4 and 6. Thirdly, the time it would take to compile and then fill out the to-do-list even in limited applications is really not worth it.
I just see almost no applications why a team would need to inform others separate from the schedule that they have completed a task on a to-do list unless anyone of the 4 people could of completed that task.
My point is, there might be a few very limited applications for this type of list but this list would be worthless as a Project Management tool in every other case.
However, change this from a to-do-list to a document change log and it is perfect. Instead of to-do it is the documents name or summary of what changed in the document. The person is who edited the document, and the time stamp is when they checked it in. But I do not know why you would use excel when there is free software you can use commercially that is 10 times better that does document management.
I think using excel to do Project Management over a real Project Management application is a bad idea. Unless you are running a very small, simple project, the time and effort is a lot more to use excel compared to the cost of the Project Management software.
This comes back to my point, I love your site, however, just because you can do something in excel does not mean you should do it. To often the time it takes to use excel is wasted 10 times over from the cost of doing it in an application designed to for the specific application.
@Brian: The todo list mentioned here is meant to keep track of all the tasks for which detailed planning is not necessary but some sort of tracking is needed. These are not be confused with project activities (a la gantt chart).
I like your suggestion about using this as a document tracker. Pretty cool use.
Coming to your point about excel as a real project management tool, well, I have my views, but in a serious project environment, it would surely payoff to have a dedicated project management application.
[...] & tracking a project plan using Gantt Charts Team To Do Lists – Project Tracking Tools Project Status Reporting – Create a Timeline to display milestones Time sheets and Resource [...]
Chandoo,
Wonder how the timestamp column will maintain its previous data. Both Today() and Now() functions will update as and when the next timestamp happens.
[...] Preparing & tracking a project plan using Gantt Charts Part2: Team To Do Lists – Project Tracking Tools Part3: Project Status Reporting – Create a Timeline to display milestones Part4: Time sheets and [...]
I've combined this with the issue tracker since I like the automatic date stamp, but one thing I'm noticing is that I can't replicate the chart that goes along with the issue tracker because the cells that are referenced have the formula that inserts the time stamp instead of a the actual date value. All the dates of the last 30 days display 0 when they should have a value.
Is there a way around this?
I have edited the chart so that my team members can update the percentage completion of the assigned tasks. When the cell is updated, i would like the time stamp to update. How would I manipulate the formula to update whenever the drop-down list is changed?
[...] … ??? To Do List [...]
Excel is great however sometimes you need to get a better idea of what tasks each person on your team is working on at any given time. We've developed a web app that can do just that! Each person has a list of tasks, listed in the order they have to complete them.
HII,
I want to expand the database through excel where i am working on 11 cities as of now and i want to expand it upto 50 cities and hence forth the data related to it will also expand so i want to make it precise where i can get updates also that this work is required to be done at that particular day or date
Thanks for making all of this information available for free. I am currently using excel to track everything for the first time. I later plan to output our information here with a more visual presentation. Wish me luck!
Can some one point me out to some additional direction on the "Who Finished it?" column? Something more 'basic' for a newbie excel guy? lol I got everything else working on this tutorial but that column. I can't seem to recreate it and I know a lot of it is due to lack of knowledge with VB code. I'd like to recreate this column very much 🙁
Dear Chandoo,
Thanks for the team to do list, kindly let me know how to set the column who " finished it " from another work sheet
Hi Chandoo,
Unable to download it - can you please check the link and confirm.
Great inhisgt! That's the answer we've been looking for.
Hi Team,
I know u all are the best programmers in the world!!! that's I am here to rectify my issues. here is my question please ans me as soon as possible before 8-3-2017 its really urgent.
I have a project named the production tracker.
1) I require the user form which shows the names of the Associates which are linked to the different tracks. when the user is selected the particular track related details and dropdowns should appear.
2) I need to track the associate needs how much of the time to complete the particular task. with start stop and pause and resume timer.
3) It should display the daily count of the production and save the data to the another Excel file.
this production tracker should save all the data no matter how many people logs in into it.
Please help me for this it will be very appreciated.
you can directly email me on my mail ID: tusharkch694@gmail.com