Any good examples of Start-to-Finish dependency?

Here is one I found..

Thanks for the example. However, it is not very convincing. "Deliver Cake" task begun is not necessary to trigger the end of "Bill Customer" task right? What about cash on delivery?

I have another interesting example though. The start of "Marriage" task is the end of "Courtship" task. The end of Courtship is not necessary lead to Marriage. However, the start of Marriage indicates the completion of Courtship. :)

Thanks for comments.

precedence types are more than four. actually their are 8 types of precedence relationships.

SS(min), SS(max), SF(min), SF(max), FS(min), FS(max), FF(min), FF(max).

the term "min" indicates that at least "x" days between start or finish of activities.

the term "max" indicates maximum of "x" days between start or finish of activities.

Maybe something related to default version of deployed application server. Once you 'start' the new version as default of a production server, then this will means the older version no longer serving/'finished'.

Based on more theoretical definition, "Start-to-Finish" refers to the relationship between two activities that the completion of successor is dependent on the initiation of its predecessor. So, the successor cannot be finished until the start of the predecessor. This is something that puzzled me. In the application server example, the new version is the successor where the older version is the predecessor. Hence, the predecessor ended triggers the start of successor, logically it is more of a Finish-to-Start example. Thus, it can't really fulfil the Start-to-Finish definition. Thanks for the suggestion anyway. Please continue to help thinking. cheers.

Try this: in a factory when the maintenace task start then the main machine stop.

The last book read finish when quiz start

the party end when start to clean the house

the normal production plan finish when a urgent production plan start

Courtship -> marriage is finish to start.

Factory machine running -> maintenance task is finish to start.

Book reading -> quiz is finish to start.

Party -> cleanup is finish to start.

etc.

Just because you say them in the wrong order doesn’t make them start to finish. Most things are finish to start. Almost all such examples are.

However, a few years ago one of my students came up with a particularly good example of start to finish (I ask them for examples when we do this topic, and they always come up with a whole load of stuff that they think is start to start, finish to finish, start to finish, but it all turns out to be yet more finish to start, just like almost everything else). Here’s her example:

In shift work, the relief shift worker has to arrive, clock in and start her shift, before the extant shift worker can clock off and end his shift. If the relief shift is late, the existing shift can’t finish. It can only finish once the following task has actually started.

I would also say that in some cases of party, if you want to make the party finish prematurely, you can start vacuuming so that everybody gets the message and goes home. However, that’s not really a dependency – the party wasn’t waiting for you to start vacuuming before it can end.

Issue is the successor cannot be finished until the start of the predecessor. Task A (Start) -> Task B (Finish)

In the shift worker example, it is the start of the successor triggers the finish of the predecessor,. It is correct as far as Start-Finish dependency is concerned. However, it is still not fulfil the start of predcessor triggers the finish of successor condition.

Anyway, if the examples are not common, this dependency might not be useful in terms of scheduling in project management.

In the discussion, I keep seeing the perspective of two activities. If you want to understand start to finish relationship, you need to see in the context of adjacent activities logic wise. Lets say activity A has SF relationship with B. So A has to start for B to finish. A has a precedessor X which has FS relationship with it. B has no relationship with X. B has a successor activity M with FS relationship. A has no relationhip with M. What we have here are two lines of related activities where the connection is only between A and B.

As an example, a flatbed truck is used for transporting equipmen from a construction site back to the storage depot. X is the flatbed transporting formwork back to depot. A is the flatbed transporting dismantled tower crane to depot. B is dismantling of tower crane. M is installing glass curtain wall panels of part of building which cannot be installed because the tower crane was in the way.

Sometimes when I explain to people, I can get confused myself, so I avoid using the SF relationship and stick to one of the other 3

Got some info from the net, i think this might be helpful.

Say you’re building a new gas pipeline. You would first finish construction and implementation of the new pipeline before you would begin shutting down and breaking down the old pipeline. Similarly, implementation of a new accounting system has to be completed before you can begin turning off the old system. Make sense?

Don’t spend too much time sweating over this particular model, however. Even though it’s not a difficult concept, the start-to-finish relationship is rarely used

Anthony,

Most of the examples you could read here are wrong.  However, here is a good one :)

For this you have to know maximal relations. The four relations you know are called minimal relations because the relation time denotes the minimum necessary time gap between the connected points of the related activities. Howevr there is an another group of precedence relations, the so called maximal relations. In these cases the lags denote the maximum allowable time between the connected points.

Now imagine a project where you build pipes in a town in dozens of different streets. Average construction time within smaller streets is 2 month but the whole project s two years, because of the main collector pipe. Logic is set within activities of individual streets using minimal relations If you make resource leveling the software can spread the activities within the shorter  street from two month to five, nine months or up to two years. If you use a maxSF 4 months between the start of the first activity in the street and the finish of the last activity of the streets then you say I do not want longer then four month construction time in minor streets.

I do not know good example for minimal SF relations. If you are interested in maximal relations then read my book from 1996. 'Network scheduling techniques for construction project management"

Dear all, thanks for the examples. During my project management classes, it is difficult to raise good examples about SF relations to the students. Most students provided the examples but they are actually FS relations. Another example I can think of is the implementation of a new IT system and turning off the old IT system. When the new IT system is fully in operation, we could then turn off the old IT system. We can't turn off the old IT system if the new IT system is not ready. 

example: 

dewatering can't finish until Concrete work on the 5th floor starts

Hi Sarah, thanks for your example. Will you like to elaborate further?

Am I correct to say that we can't turn off the dewatering until the Concrete work on the 5th floor starts? Is the concrete work triggered the completion of dewatering?

Hi ,

I have two other examples, I hope these fit to SF. 

1. "Progress payment documents and payment itself" For starting of the payment all progress payment documents have to be approved.

2. In the renovation projects for starting of the drywall installation removal of existing ones have to be finished. 

I am only commencing my comprehension of these principles. but for an example of start-finish; That comes to my mind could be that of adultery.

For example one would have to be married, in order to cheat, and the marriage cannot have ended before the cheating began. 

Hi Con, interesting example. Another similar example: Start of Marriage triggers the End of Boyfriend-Girlfriend or courtship relationship.

Hello Anthony. I feel I have a good grasp of this Start-Finish dependency now. Another example I now refer to in regard to this scenario, is that of Leadership change in most democratic nations, i.e. a Leader can not be deposed, or removed from their position of power until the next incumbent is sworn into power by taking an oath of office or what have you. Only then can they then assume the title EX Prime Minister, etc.

That is correct. For Start-Finish dependency, Task A could not finish until Task B started. For instance, the duty officer of the current shift has to continue his job until the next shift duty officer started his job. Technically, even the next shift duty office is late for work, the previous shift duty officer is required to continue to work till someone to take over.

Do not for get it is about dependencies. The First task cannot finish until the second task starts. So a duty relief situation is truly Start to Finish. The first item in the dependency statement is the event that triggers the second item. Finish or Start will be the event of the Preceding task (first of the two) and Start is usually the event of the Depending task (second of the two).

SF = Start of second task triggers finish of the first (generally no delay)

FS = Finish of first task triggers start of second (may be a delay too)

SS = Start of first task triggers start of second (may be a delay too)

FF = Finish of first task triggers finish of second (may be a delay too)

If we draw the dependency like that: [Finish (A) <- Start (B)], it's better to understand the meaning. For Windows it's simple: You must press "Start" to "end" the operating system. (joke). It cannot be treated as a good example because those tasks are not independent.

My example:

assumption: sports betting is not legal

task A -> earn money (win) in sports betting

task B -> sports betting legalization

So, you can play in sports betting and win, but the money transfer (finish of task A) is possible only when the sports betting are become legal (and you won, of course - but this is another story).

These tasks A and B are completely independent.