ABB Targets

1
ABB Targets

• Automation Industry requirements
• System should execute in a predictable and safe
  way at minimum cost
• Fault tolerance is important
• Ergonomically correct to minimize human error
• Integration of different functions
• Scalable Distributed as well as local
• Open and allow inter-operability with 3rd party
  software
• Secure
• Should support COTS as well as plug-and-produce
  capabilities

2
Platform and topological issues (sketch)
3
The ABB Aspect System

• Aspect
• Defines a piece of information as well as methods
  to manipulate, access, create the information
• Aspect Object
• A container that holds references to Aspects
  which implement its behavior
• Composite Aspect Object
• To denote containment of Aspect Objects within
  other Aspect Objects (Aggregation)
• Aspect Type
• Actual implementation of an Aspect
• Aspect Category
• A notion to further group Aspect Types

4
The ABB Aspect System (cont)

• Aspect Object Type
• Defines characteristics shared by several Aspect
  Objects.
• Composite Aspect Object Type
• Describes a set of Aspect Objects and their
  organization structure
• Aspect System
• Implements one or more aspect types

5
Look and Feel

• Aspects
• Appear to be a more constraint definition of an
  Object as in OOP
• Aspect Objects
• Open classes that strictly hold references to
  Aspects
• Composite, Aspect Types, Aspect Systems,
  Categories
• Extended grouping facilities to allow management
  and easier development.
• Gain back of OOP structure and Types.
• Technology (.COM/.NET)
• Distributed management and operation
• Ease of extension (open classes feature)
• Reusable (Aspects as well as Aspect Objects)
• Ease of integration with industrial specific
  hardware and standards

6
Good Ideas

• Encapsulate each property separately (fine
  grained aspects)
• Compose your entities by using the appropriate
  properties that they should have
• Allow both properties as well as entities to be
  reusable as well as easily extensible
• System openness and support of COTS
• Allow the disassociation of code reuse from
  behavior reuse

7
From ideas to AOSD

• Fine grained Aspects
• H/W 3 pointed out that a good rule of thumb is
  make your advice simple and your pointcuts rich
• Introductions in AspectJ are a nice way to
  extend/manipulate new behavior (open classes)
• Reuse in AspectJ limits itself to OO structures
  either in Classes or Aspects (abstract, concrete,
  interfaces)
• COTS not there yet (AspectJ needs source
  code)!!!
• You inherit ? Subtype

8
Pitfalls

• Fine grained Aspects
• But then I get a LOT of little pieces of code.
  How do you work around that ?
• With all these pieces of code, composing becomes
  not as easy as you make it out to be
• If too generic might capture more than you
  actually need
• If too specific, then it becomes cumbersome to
  write all the details
• Debugging nightmare !?!?
• How do I deal with non-orthogonal
  aspects/components once I start plugging in(out)
  aspects/components ?
• Integration needs to be guarded against
  malicious/erroneous code introductions.
• Security needs to be verified at deployment.