topical media & game development
object-oriented programming
Business objects -- SanFrancisco framework
What are business objects?
From the perspective of typical business end-users,
that is
accountants, engineers, managers, business objects
provide access to corporate information.
Traditionally, corporate information resides in
legacy databases, and access means looking at tables
and pasting these into documents.
Business objects
- access to (relational) data
Designer -- define data model
- universes, classes, objects -- shield from tables
Business user -- deploy views
- select, order, summarize, aggregate, tabulate
slide: Business objects
Even within this kind of limited usage, it makes sense
to speak of business objects,
as a way to shield the user from
the actual structure of the underlying (relational) database
and the use of query languages such as SQL to obtain
the actual data, see [BO].
Business objects, as a metaphor for bringing information to
the desktop, allow for accessing corporate databases
in a transparent manner, and for
building the tools that allow business end-users to extract information
from the database in a flexible way, and to use this information
for further analysis and manipulation.
In [BO], a distinction is made between three types of
end-users involved in the construction and use of business objects.
The designer, who creates the objects
that act as an interface to the database,
the actual end user, who uses these objects to
obtain information (and thus implicitly creates queries),
and the supervisor,
who provides users with access to the various regions or
universes defined for the database.
The actual business objects toolset, described in [BO],
provides a GUI-based drawing tool to create queries
by composing objects and creating relations between objects.
Business objects, then, are a means to access corporate data.
This is
a first, but nonetheless important, step.
An immediate advantage, obviously, is that
business objects may be defined according to actual business
needs, instead of being dictated by (relational) technology.
More generally, business objects may be regarded as
abstractions underlying the definition of business processes.
In the following we will explore whether we can
generically define business processes and
whether there is a collection of abstractions
that we may denote as business objects.
The SanFrancisco framework
\label{San Francisco}
The SanFrancisco framework (IBM) is an example
of a framework meant to develop business applications.
A business application, as we understand it here,
is an application that deploys business objects
to (partially) automate business processes,
such as order or warehouse management.
(Business) frameworks
- collection of components
- generic solution for a class of problems
- frame of mind for solving problems
- set of architectural constraints
slide: Business frameworks
A framework is a collection of components, but may also
be considered as a generic solution for a class of problems.
It sets a frame of mind for solving problems
and provides the means to realize solutions in software.
In practice, adopting a framework means accepting a set
of architectural constraints.
slide: The SanFrancisco framework
As a framework, SanFrancisco aims at providing
both a software solution for implementing
business applications, as well as a collection
of concepts or strategies to develop effective
business applications.
In the white paper accompanying the introduction of
the SanFrancisco framework, we read that the project
was started when several software vendors
asked IBM to help in modernizing their application products.
These vendors asked for help because
there were several barriers that prevented them
from modernizing their applications themselves.
Barriers such as (1) the risk in moving to
new technologies (such as client/server and the Web),
(2) the need to retrain their development staff
to effectively use an object-oriented approach,
(3) the cost of change.
As the white paper states,
as software developers they needed some
basic infrastructure, and most companies could
not afford to develop this infrastructure themselves.
The SanFrancisco framework provides such an infrastucture,
and moreover, the white paper claims, an object-oriented
infrastructure that provides a consistent
application programming model, with many well-tested
services and a collection of core business process components
and common business objects.
core business processes
- Accounts Receivable/Payable
- General Ledger
- Sales Order Management
- Purchase Order Management
common business objects
- Business Partner, Address, Number, Currency
foundation object model classes
- Command, Entity, Dependent, Collection/Iterator, Factory
slide: SanFrancisco object layers
The SanFrancisco framework offers three layers of functionality,
business processes, business objects, and foundation classes,
each of which may be used and extended by developers
to build their applications.
The process layer itself may be regarded as
a collection of frameworks, as indicated in slide [sf-layers],
which build upon the business objects and foundation layers.
Note that the foundation layer contains realizations
of the by now familiar patterns, see chapter 2.
slide: Refining quality control
The SanFrancisco framework is an object-oriented framework.
It allows for the classical way of extending the framework,
by inheritance.
As an example, think of a Receipt object
which may contain an arbitrary number of
Purchase Order Line instances, see slide [sf-example].
Purchase Order Line has an attribute
Quality inspect which is read by Receipt
to determine whether quality control is needed.
This reflects the default (business) logic for processing orders
as defined by the framework.
To enhance this logic, that is to be able to
execute more strict quality control, one may derive
a new Receipt class from the old Receipt
class and override the method by which to determine
whether quality inspection is required,
for example by including a check on the supplier,
previous outcomes of quality control,
or whether it concerns hazardous materials
or high-value products.
As a remark, note that this approach assumes
that the business logic is to a large extent
hardwired in the (structure of the) classes of
the framework,
whereas a decoupling of the logic and the actual
processing might be preferable.
Discussion
The SanFrancisco framework is based on Java technology.
Its introduction marks the transition
towards client/server and Web technology, and clearly
addresses the need for many companies to migrate
to the new technology.
Apart from technological considerations, however,
the major issue in adopting a framework
such as the SanFrancisco framework
is whether it sufficiently reflects emerging
consensus and standards concerning the definition
and utilization of business objects and processes.
Related efforts of business object standardization
are undertaken by the OMG.
On the technology side, it is difficult to establish
who will win the component war, Java, OMG CORBA,
or Microsoft (D)COM and ActiveX.
(C) Æliens
04/09/2009
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