Functional consultants (i.e) example fico consultant 
provide their requirements for exexuting the sap projects 
according to clients requirements.

1.  it is prepared by functional consulants.
2.  based on clients requirements.
3.  for  new customisation also this required.

Hi,
The Functional Spec (Specification) which is a comprehensive
document is created after the (SRS) Software Requirements
Document. It provides more details on selected items
originally described in the Software Requirements Template.
Elsewhere organizations combine these two documents into a
single document.

The Functional Specification describes the features of the
desired functionality.. It describes the product's features
as seen by the stake holders,and contains the technical
information and the  data needed for the design and
development. 

The Functional Specification defines what the functionality
will be of a particular area that is to be precise a
transaction in SAP terminology.

The Functional Specification document to create a detailed
design document that explains in detail how the software
will be designed and developed. 

The functional specification translates the Software
Requirements template into a technical description which
   
a) Ensures that the product feature requirements are
correctly understood before moving into the next step, that
is technical development  process. 
   
b) Clearly and unambiguously provides all the information
necessary for the technical consultants to develop the objects.
   
At the consultant level the functional spects are prepared
by functional consultants on any functionality for the
purpose of getting the same functionality designed by the
technical people as most of the times the functionalities
according to the requirements of the clients are not
available on ready made basis.

Let me throw some light on documentation which is prepared
before and in a project: 
The project normally starts off  with a Kick off meeting in
which the team size, team members, reporting system,
responsibilities, duties, methodology, dates and schedules,
working hours which have been decided are formally defined.

Functional consultant is expected to generate knowledge
about the current business process, design current business
flows, study current business processes and its
complication, in all we can say getting through with current
business setup. Flow diagrams and DFD are prepared, most of
the time in Vision format, all this forms the part of AS IS
document.

Everything configured has to be documented as per their
categories in the form of predefined templates, these have
to be then approved by the team leads or who ever the
consultant is reporting to.

Mapping and GAP analysis is done for each module, I have
seen people defining integration after mapping, gap analysis
and configuration is done, but as per my experience in
implementation, it is a simultaneous process.

Before starting configuring  future business processes in
SAP, the DFD/ERD are prepared, this documentation is called
TO BE, which can be also siad as the result of mapping and
gap analysis.

Sometimes Functional consultants are also expected to
prepare End user manual, provide training and also 
interacting with Abapers to develop any user exits.

The consultant takes care that the system is usable,
performing appropriately and the business flow is complete
and correct. 

During go live he assists the technical staff by testing the
behaviour of the system. 

After go live he guarantees that the procedures remain
usable and consistent in real live situation and proposes
enhancements.  

Thank you.