1. What is Outlier group In APO?

Not sure if outlier group exist in APO.....

Outlier: Lets say you have planned your expenses @ 500 $ per
month. However due to festivities you see sudden spike in
your expenses in the month of Oct, Nov and Dec (say by 400
). Your annual forecast was 6000 but due to recent 3 month
activity actual is 7200. These spikes are called outlier.

Smoothing: When you account for these changes over a period
of time (even distribution). In this case it would be 600
per month instead of 500 till Sept and 900 for Oct, Nov & Dec.

2. What is consensus forecast?how its used?what are the FORECAST models involved in?

Consensus forecast refers to a business process, not a
system function. It basically means forecast created with
the mutual agreement of the various business functions,
e.g. supply chain, finance, sales, etc.
As such it is not linked to any statistical forecast models
(I assume you meant that) and you can use any and all
models, it will not create a consensus forecast for you.
You have to take your numbers and discuss and agree about
them with your colleagues of the different departments.
That's what will make your forecast consensus based.

3. What is meant by functional specifications involved in poand ap?

Functional specifications are needs to prepared and given
by functional consultant to the technical team or ABAP
Consultant.. so that they make enhancements..develop as per
clients requirements.

Asume that you have purchase report: which contains
characters and key figures.. such as PO DATE, MATEIRAL
NUMBER, MATERIAL DESCRIPTION, PO VALUE" AND AND SO ON.. BUT
standard report does'nt support for client's for eg..Total
consumption at production or Qty used it for manufacturing"

One has to give specifications..such why it is required,
what is the use of new object, what specifications are
required to develop by ABAP TEAM..

4. How to find out one organization using multi-org or single org?

If i am not wrong looking at the company code available on
the system will tell us weather its single or multiple
organisation

5. What type of Questions can they ask on Personnel Management?

they can ask about your goals and objectives
hobbies sometimes to know u r learning capabilites
y did u quit the earlier orgnanisation n so on this is
what i was asked