Today we will discuss fast-tracking vs crashing, the two schedule compression techniques.
There are many reasons why you might need to compress the schedule.
For example, your project is delayed, and you must bring it back on schedule. Perhaps management asks you to compress the schedule, which often happens when your resources are needed for a new opportunity.
Project delays can happen for many reasons:
- An unrealistic schedule
- Unavailability of promised resources
- The occurrence of unidentified risks
- Force majeure
Other reasons for using schedule compression techniques include:
- The client wants you to complete the project early.
- You have an opportunity to get another project if the current one completes early.
- You want to launch a product early because a competitor has done so.
You can use one of two schedule compression techniques, fast-tracking and crashing, to decrease the project’s duration with no change in scope.
Fast Tracking Vs Crashing
Let’s start with fast-tracking.
Fast-Tracking
The PMBOK Guide, 6th edition, defines fast-tracking as a schedule compression technique in which activities or phases normally performed in a sequence are done in parallel for at least a portion of their duration.
In fast-tracking, you review the critical path and list all vital activities. Then you analyze and determine which ones can be performed partially or fully parallel with other activities.
You don’t need to review the activities on the non-critical paths, as they have float, sometimes known as slack, the allowable delay before the overall project is affected. Reducing the duration of those activities will not affect the schedule; it will only allow more float to them.
You should monitor other paths whose durations are close to the critical path. If any other path becomes critical, you will need to reduce the duration of the new critical path. In this case, your current path will no longer be critical.
Accordingly, you will then rearrange the fast-tracked activities and reanalyze the schedule.
Project managers start with fast-tracking to compress the schedule because it does not cost more. However, it increases risk as activities overlap.
As a rule of thumb, you can fast-track sequential activities by 33%. This means you can start the next activity when the previous is 66% complete. Both activities partially overlap, increasing the risk but within acceptable limits.
Fast-tracking helps you compress the schedule up to certain limits. Continuing beyond that limit will increase the risk, which may lead to rework and further delays.
Example of Fast-Tracking
Let’s say that you are building a school and the initial construction work is about to finish. Next, you have planned to start carpentry and electrical work.
When you review your progress, you see that you are behind schedule; consequently, you have to move faster to complete the project on time.
You will review the carpentry and electrical work activities and decide if you can perform them in parallel. If so, you can apply fast-tracking.
In this case, you can start the electrical and carpentry work simultaneously, allowing you to speed up the schedule.
Lead Vs Fast-Tracking
On a compressed network diagram, activities with lead and fast-track activities look the same. Hence, many aspirants often think the lead is the same as fast-tracking, but there is a significant difference.
Lead is a type of dependency that you use while developing a network diagram. It is already factored into the schedule. On the other hand, fast-tracking is a forced overlap. You do it to shorten the schedule. Fast-tracking increases risks and potential rework, while lead is a dependency type on the network diagram and does not affect the risk.
Crashing
The PMBOK Guide, 6th edition, defines crashing as a technique used to shorten the schedule duration for the lowest incremental cost by adding resources.
In crashing, you review the critical path activities and find ones that can be completed early with extra resources, providing the highest compression with the least cost. In other words, you add labor, resources, and anything you can to speed up the process, crashing the activities.
A few examples of crashing techniques are:
- Overtime
- More resources
- Monetary rewards
While crashing, you will monitor other paths as well. It is possible that the duration of other paths could become equal to or greater than your critical path.
Initially, you will get a greater reduction in duration with less input cost. However, as you continue further, the cost will increase, and the reduction will dwindle.
Therefore, do a cost-benefit analysis.
Crashing cannot be applied to all activities.
For example, you have to wait until the concrete dries before starting your next activity; there’s no way to speed up that process.
Example of Crashing
You are constructing a room. According to the duration estimate, two masons will take four days to complete it.
You can reduce the duration of this activity by crashing, and adding two more masons to complete the task in two days.
Sometimes, crashing may not produce the desired result. Getting skilled resources is not easy, and they take time to settle. You cannot bring in a new group of people and expect them to perform immediately.
Therefore, it is possible that the cost will increase with no significant gain. Make sure you perform due diligence before crashing to determine if it’s worth the cost.
Difference Between Fast-Tracking and Crashing
The following are a few differences between fast-tracking and crashing:
- In fast-tracking, activities are rescheduled to be performed partially or fully in parallel, while in crashing, you add extra resources to the activities to finish them early.
- Fast-tracking does not cost you extra money; crashing does.
- Fast-tracking increases risks. Crashing does not, significantly.
- You use fast-tracking when activities can be overlapped to decrease their duration, while you use crashing on those where adding extra resources can decrease their duration.
When Should You Use Fast-Tracking or Crashing?
This depends on your situation and requirements.
For example, if the client wants to complete the project early and is willing to pay, use crashing.
Generally, you will start with fast-tracking to shorten the schedule. If fast-tracking doesn’t yield the desired results, shift to crashing.
Sometimes you may use both techniques. For example, the client is threatening to fine you for the delay. To avoid this, you will compare the cost of crashing with the fine. If the crashing cost outweighs the fine, you will use it with fast-tracking for maximum schedule compression.
You may also use crashing if the project delay will negatively affect the company’s image or credibility.
Why Do You Apply Schedule Compression Techniques to the Critical Path?
As the name suggests, these are schedule compression techniques. The schedule is based on the critical path, the longest path of the network diagram, and its duration is that of the project.
Reducing other paths won’t reduce the duration of your project; it simply gives those paths more float.
If you want to reduce the schedule duration, you have to shorten the duration of the critical path.
Summary
Projects often get delayed, and you have to compress the schedule; fast-tracking and crashing are two ways to do that. These schedule compression techniques help you decrease the duration of your project. Fast-tracking does not involve cost, but it does increase risk. Crashing does not significantly increase risk, but it is a costly process. Use these techniques carefully because you are dealing with critical activities. Any wrong step can affect your project negatively.
Schedule compression techniques (Fast-tracking and crashing) are essential techniques in project management. They are also crucial for the PMP exam; therefore, understand these techniques well.
How do you perform fast tracking and crashing in your projects? Please share your thoughts in the comments section.
I am Mohammad Fahad Usmani, B.E. PMP, PMI-RMP. I have been blogging on project management topics since 2011. To date, thousands of professionals have passed the PMP exam using my resources.
Thank you so much! Very well written. I learned a lot.
You are welcome Holly.
super explanation ,,, thamx a lot Fahad
You are welcome Hamad.
Thank you. It’s helpful.
You are welcome Fridah.
i have learnt a lot
thanks very much
You are welcome Mr. Adarkwa.
it was really good topic. Thanks for detail explanation.
You are welcome Kamran.
Thanx its really good
You are welcome Max.
Explained well..!!
Thanks Rashid.
Good and useful comments.
Thanks guys
You are welcome Moses.
Very greatful being a student of pmp it keeps me going
Thanks Isaac for your comment.
thanks very much, this project has adequately prepared me for a project management exam
fast tracking and crushing now understood
I am glad Tannet that I could be of some help to you.
Just what I was looking for, very good display of knowledge.
Thanks Michael.
Please help me with this query:
Out of fast tracking & Crashing, which technique one should use when network diagram cannot be changed.
For reference this is the exact question:
Q. After completing the schedule network analysis, you find out that your project schedule is taking too long and you also find that you cannot change your network diagram. In such cases, in order to get the project completed faster, what option do you have?
A. Nothing can be done
B. Crash the project
C. Perform resource leveling
D. Fast track the project
well explained. thank you so much.
You are welcome Suresh.
Thank you very much for this resource.
You are welcome CHIMEZE.
thank you so much
i am taking the exam this Friday
I will use what i learned here
You are welcome Erica. Good luck on your exam.
I am enjoying a lot to read the content. This article is beneficial for me. I understand where which technique is used.
Thanks a lot.
Abuzar Azmi
You are welcome Abuzar.
Hi
thanks for your explanation and please could you give me examples or risks in fast tracking method?
Please read the following article:
http://www.sciencedirect.com/science/article/pii/S1877705811013981
Hi..very gud explanation..what is the difference between resource levelling and resource smoothing?is related material available in pmstudycircle?
Hello Jai, soon I am going to write a blog post on this topic where I will explain it with detail.
Thanks for your explanation.Its very simple and easy to understand as now i have the correct idea of fast track and crashing.
Thanks once again.
Ubaidur Rehman
You are welcome Ubaid.
Very nice article. You have explained it in simplest way !!
Thanks Abhilash for you comment.
Very well explained.
Very easy to understand the core concepts of PMP topics from this blog.
Thanks Sarfaraz for your comment.
Thanks a bunch!
You are welcome Benjamin.
Very Nice Article..
Thanks Shiva for your comment.
It is not simple math. It is not necessary that four labor finish a work in 10 days then 8 labor will finish in 5 days. Many times, it takes more and the cost of newly acquired labor will be higher than your current labor. You may also need some equipment or material at urgent basis which you planned to used later, this may also cost more.
Thank you for making it simple. Very good explanations!
Great stuff well explained
Thanks Shava.
you are great man… thumbs up :)
Thanks Raja.
Great Fahad ! Many thanks
You are welcome Konan.
Very nice post and you have explained the compression technique in a simple manner.
However, I am not clear with “Usually sequential activities can sometime be fast tracked by 33%. This mean if the previous activity is 66% completed, you can start next activity. Here, both activities will be partially overlapped” statement. Can you please elaborate the same?
Thanks for your help in advance.
It depends. Sometimes you are able to finish an activity before its actual finish date and start next activity before its actual start. Other times you can start next activity before completing the previous activity.
Very simple and comprehensive explanation of schedule compression. Just like to add one thing:
There is another disadvantage of these techniques that they disturb the cash out-flows and create more nuisance for the Finance Manager, at times.
Thanks
Right Mr Baddar.
If there is a scope change request by the client. First the PM will document the change request, then he will evaluate/assess the change to understand if there is any impact on other projet constraints. If he find that the scope change will affect the schedule. So he looked for an option to fast track the critical paths. My question is does he need a separate approval for doing fast tracking ?
Fast tracking usually does not require any approval, how you need to communicate it to the concerned stakeholders.
Hi Fahad,
Thanks for detail explanation. Not directly related to fast tracking but I have following scenario regarding change requests if you can have a look.
Say when measuring current project performance, variations are encountered and degree of variation is determined. Now to bring the performance back on track, corrective action is recommended.
The request is documented and change request is created, entered into change log, and evaluated, detail impact is analyzed against constraints and various options are identified to address the change.
The Change does not impact project management Plan or its subsidiary plans or project documents neither it has an impact to performance measurement baselines.
So in the above case still submission to CCB for approval is required? or such cases are at discretion of project manager to decide.
Some where I read a statement every change request (including corrective, preventive and defect repair) would need to go to CCB for approval or rejection, so got confused!!
Thanks
Sushil
You will have to built in your plan. If the plan says that every change request should go through the CCB regardless it affects any parameters or not, your change request will go through it.
Usually if any change request does not impact any parameter, does not go through the CCB. You should only document it.
Thanks Fahad, Does this applies considering PMBOK point of view.
“Usually if any change request does not impact any parameter, does not go through the CCB. You should only document it.”
So can i conclude every change request may or may not be submitted to CCB for approval which depends upon the change management plan or considering management by exception.
You have to document every change request whether it impact any project objective or not.
Regarding the CCB process, you can define it in your project plan.
Question – if compressing the schedule (ex. fast tracking), to bring a project back to meet the end target date, would a change request be required?
My guess is not in this case.
But I imagine if the fast track did impact the schedule baseline (i.e. move it up) then a change request would be required.
Would appreciate your opinion! Thanks
As per my understanding, you are right.
Really I would like to thank you so much to these simplicity in explanation.
You are welcome Nasser.
What is the effectivenes of crashing techniques in project schedule based on construction?
In crashing you add more resources such as increasing the number of labors, which helps you complete the task earlier.
Crashing means also giving
overtimes for the team work and cost the hour of the overtime equal 1.5 the hour of duty … I wanted to explain that the crashing costs incremental money.
Khalid Elagmy
It depends on company’s policy. Some companies give 1.25 times other give 1.5 in normal days. In holiday this may go up to 2 times.
If there is a current talent work pool at a construction site could I crash project by reallocation resources which may not cost more
Yes, you can do it.
When schedule and budget are changed means only that time scope is changed or there are some other reasons that may also bring change in scope? If they are what are they?
If clients wants to do a small change in product scope such as scope, can we do it or we have to go through change control system?
There are many factors that can lead to change in scope. For example, market condition, occurrence of any unidentified risks, or it is just a client request.
Every change needs to be documented and if the change require modification in any baseline, it has to be go through the change control system.
Assalam-o-Alaikum
Fahad Usmani
In Fast Tracking when we go from sequenced planning to paralleled planning for schedule compression, why we do not need extra money or resources such as labor, keep in consideration that our limited amount of resources or labor are involved in doing sequenced activity, let say at least one activity ( resources will go to the next activity after finishing current activity) while in doing activities in parallel our resources or labor are involved in doing at least 2 activities (More money, resources or labor will not be required in this case to perform 2 activities at the same time, will not cause duplication of resources in order to get the activities done at the same time in order to save time.
Thanks
First of all, you will review all activities, and if you find a few activities that can be performed parallel or partially parallel, you will go for it.
For example, let’s say you have two activities in sequences: carpentry and electrical works. These two activities will be performed by different people at different time. Now you review these activities and find that you can run these two activities parallel.
So you called these guys to work in parallel. In this case neither you have to spend more money, nor bring extra labor.
Hope it helps.
Hi,
Everything is perfectly explained and thanks for that but same time why didnt you add its merit and demerits for better understand.
Looking forward with answer.
Good suggestion Dorji.
I have noted your advise, and soon I will update this blog post with merits and demerits of fast tracking and crashing.
How crashing affects the overall project goal and strategy ?
Effectiveness of crashing technique in project management for industry ?
Since crashing involves cost, it may affect your cost baseline.
Give me example about crashing management
I did not understand what did you mean?
Hi Venkat,
You need to consider the LAW of Diminishing Returns ” The marginal productivity of the workforce decreases as output increases, diminishing returns do not mean negative returns until (in this example) the number of workers exceeds the available work space.”.
What Mr. Fahad was explained same thing in his reply.
Hi Fahad,
All of your blog post are very nice and clear.
Compare to other blog posts, I think you forgot to elaborate Risk while Fastrack and Rework while Crashing with examples. Any way its nice.
Thanks,
Lax
Hello Lax,
Soon I will update this blog with more detail…
Hello All
Can someone please share their thoughts for this one?
I don’t want to type in the entire question, but basically you are under budget and 3 weeks behind schedule. After an EAC assessment, your values are ($450,000) and it will require 4 more weeks to complete the project. What should you do?
a)crash b) fast track (the other 2 options are goldplate and outsource..ridiculous I know)
I picked a) crash, because I thought since you are under budget, its not a constraint for you, you can add in more resources, more experts..whatever the money can afford you to complete the project sooner, with the advantage of lesser risk as compared to the correct answer of b) fast track. But doesn’t fast track introduce more risk?
Even if you are under budget, you will first look for fast tracking because it saves money. If it is not possible, you will go crashing.
By how many days can we crash an activity at a time?
It depends on many factors, such as duration of the activity, duration of successor and predecessor activity, its relationship with other activities, resource available with you and finally whether the activity can be crashed or not.
There is no universal answer to this question as the project manager has to take decision based on many things…
Hi,
I have one question regarding crashing will increase the cost of the activity.
I have an activity in which two guys are working and it would take 4 days to complete the work. The charge for these guys is say $100 per day. So for 4 days it will take $800. Now if I add two more resource and now four guys can complete the same work in 2 days. Still the cost is same $800.
I have used crashing technique to do schedule compression but the cost has remained same. Where is the cost increase..
Venkat
It is not always possible that if a job can be finished by 2 guys in 4 days, you add 2 more guys and job is finished in 2 days.
Why?
Because there is always a decay in efficiency in performance if you bring more guys to the activity to complete task sooner.
I mean, if 2 guys finish a job in 10 days, then 4 guy may finish this job in either 5 days or 6 days. It is not always true that they will finish the job in 5 days.
It may also be possible that the new guys may have the less skill than the guys you have because your old guys have a experience in handling the task and are selected just because of that.
Moreover, since you are bringing new guys in hurry, you may have to pay them higher than they guys already working on your project.
Also, assume that you have 2 heavy equipment with you. Since you want to finish this job early, you are renting two more equipment from open market, which will cost you a lot.
Same is true for consumables, you may end up purchasing them at higher price.
There is also a chance of rework…
Point is, there are many possibilities that can increase the cost. It is just not only the human resource, there are others factors impacting it as well…
on the question/proposal of venkat , i want to comment an example ……….
One Woman can give a child birth / produce one baby in nine months, now 9 women jointly can’t produce one baby in one month.
So, depends on nature of work and way of work.
want to add something to your answer on Venkat question:
even though we pay 800$ in both cases, it’s not the same thing. because we pay 800$ in only 2 days and there is a link between cost and schedule.
also, maybe the resource is paid for the whole work, not per day or per worked hours, hence, if you pay 400$ each resource, you’ll be paying 1600$ for 4 resources :)
Am really understand the explaination. Thanks so much, may alimighy God continue to bless you.
Thanks for your visit.
Awesome i got the explanation. Great to have people like you on the face of earth.God will continue to increase your Knowledge and Understanding.
Bada.
Thank you Bada.
thank you helped a lot
You are welcome Eddie.