Process Integration or PI forms one of the components of SAP’s
NetWeaver along with other components such as Business Intelligence (BI),
Master Data Management (MDM) and so on.
Earlier when PI was not available, data communication between
multiple systems was very time consuming and very confusing to design,
configure and track. Hence it was called a spider web connection. As seen in
Figure 1 below, even an addition of one system to the network needed too much
of coding and configuration to make the new system communicate with other
systems in the network. As seen in
Figure 2 below, with PI coming in as a middleware, it avoided this extra work.
Adding an extra system needed only 2 more extra connections, one from PI to new
system and from new system to PI box.
Figure 1:
Spider Web Connection
Figure 2:
Advantage PI: A single point of integration for all systems, SAP and non-SAP
From the figure above, if all the systems were to know XML, then
work will get so simple. This is where our PI middleware comes into picture. PI
middleware has a component called ‘Adapter’ which helps in this data conversion
from XML to any format and vice versa.
Some examples of middleware products other than PI in the market
are SeeBeyond, TIBCO, etc.
Now, let us briefly see the various components of SAP PI:
Figure 3:
Components of PI
Take a look at the Figure 3 above. Let’s briefly see what these
important components of PI do:
a.
System Landscape Directory (SLD) : SLD contains
the info about the set of systems in the organization and their details like
system name (HR, MM, SD, etc.), products installed, their versions etc., SLD is
not a component of PI but a part of NetWeaver. PI uses some components of SLD.
b.
Integration Repository or Enterprise Services
Repository (IR or ESR): The design time
component of PI, the Source & target structures is defined in repository
box (IR or ESR). Mapping is also done in IR box where mapping means converting
source structure to target structure.
Key functions of the IR or ESR box are:
1.
Creating the Structures (Source and Target).
2.
Mapping the Structures.
c.
Integration Directory (ID): The configuration
time component of PI.
Key functions of the ID box are:
1.
Helps in connecting 2 systems (Source &
Target).
2.
Configuration of the scenario.
d.
Adapter Engine (AE): AE converts any data to XML
and vice versa. In case of SAP system as target, Adapter will convert XML to
IDOCS or RFC. Same way, if source is a SAP system, IDOC/RFC will be converted
to XML by the AE module.
e.
Integration Engine (IE): IE is a runtime
component of PI which helps in message transformation as per the configuration
made in the Integration Directory.
f.
Business Process Engine (BPE): With the help
of a graphical process editor it controls message correlations and how messages
are processed as part of cross component Business Process Management (ccBPM).
This will be helpful in creating cross-system process for processing messages.
g.
Partner Connectivity Kit (PCK): PCK is a
development java library freely downloadable. You can write your own program if
there is a new format of data other than supported ones like IDOC, RFC etc.,
Market Place adapters are 3rd party programs that have to be
certified by SAP. This is created using PCK or adapter specification.
h.
Proxy: It is an alternative for adapter. There are 2 types of proxies i.e.; Java &
ABAP. Sometimes adapters won’t be there for a particular application and
instead we can use Proxy. Proxy thus avoids PCK.
To understand PI in the simplest manner, let is imagine 3 Boxes as
seen in Figure 4 below. Source box and Target box can be SAP or Non SAP. PI
middleware uses standard XML format for communication. Hence, Input and Output
of PI box will be XML.
Figure 4:
The 3 Boxes
