1) What is WBS element?
 2) What is the Tcode to get to that screen?
 3) What is the need and pupose of WBS element?
 4) Do we happen to work on Functional module during our implementaion project?
 5) In what scenario/situation we will be working on WBS?

WBS is nothing but Work Breakdown Structure. It is mainly used in Project System (PS) module. Tcode : CJ20N

For any project defined we must have atleast one WBS. Within this WBS we can have networks. Networks are nothing but the series of activities. Material are used to perform the activities.

To explain in detail just consider one example:

Govt of india wants to have Roads to be build through out the india. So Project can be defined in sap as "Connectivity".

WBS can be roads within different states like Roads for Gujarat, Karnataka etc.. i.e. WBS Gujarat, WBS Karnataka etc.

We can define different networks for these WBS  like Road Between Ahmedabad to Surat or Between Bangalore to Belgham.

For this network we can have many activities like Land selection, Land Preparation, Road Building, Final finishing etc etc.
 

Hemal's example was a good example. Project Systems comes into play only when the industry's business is based on projects like... Construction companies, Engineer to Order scenarios. You may not see anyone using PS module for retail business. As Hemal explained in that example, you have a main project which is broken down into WBS elements. You can use the TC CJ20N to create the project and the WBS elements. Each WBS may have mutiple Networks associated and each Network may have multiple Network Activities as explained in the example by Hemal.
   
On the Sales Order, if your client is implementing PS module, you may have to attach the Sales Order to the WBS element it belongs to. WBS element is nothing but a bucket where all the activities belonging to that particular part of the project are captured. In the example, WBS Gujurat will tell you how many Sales Orders were created for the Gujurat sector, howmuch was spent on raw materials, what's the currect stock ([roject stock) available. How many Production Orders have been confirmed and howmany of them are getting confrmed in the future. How many invoices have been generated or how much revenue has been generated for that particular sector. How many deliveries have been made, what deliverables are still not accomplished. 
   
So as you can see, PS is the center stage for all the modules that are being implemented like FI/CO, SD, MM, PP in this example. You can have cost centers and work centers defined. You can also have profit centers assigned at the plant level and get reports on varius selection criteria. 
   
In a complete cycle of PS, like in reality, you initiate a project, you confirm/release the WBS/activities as per requirement, you execute the project and you close it. 
   
One cannot initiate an activity unless it has been released by the project manager. Everything is accountable here and every dime is counted and at the end you know howmuch did you spend or make on each sector (WBS). Dont get confused with the term sector here... I am using it just for the explaination purposes. :)
   
In one typical example, the company I was working with until not too long ago, had Deliveries from the Project (TC: CNS0). We never used VL01N. We used CNS0 to create a delivery and then used VL02N for confirming the picking quantity for the already created delivery document.
   
I hope this should help you at least a bit. I'm not a PS consultant so I may not know a whole lot but trying going to CJ20N and you will see a lot yourself. 
   
PS concultants are one of the highest paid consultants. Their supply is less and so is the demand. They are expected to understand real world business processes very well and they are generally the center stage of a project.

Tips by : Hemal, Kunal

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