DDD and RM-ODP #1

DDD (Domain-Driven Design) book suggests strong connection between model and implementation.  The model elements introduced include Associations, Entities, Value Objects, Services, and Modules.  

1) If we consider Entities, Value Objects, and Services concepts in RM-ODP terms, are they something similar to Information Viewpoint Objects and ODP functions?

2) DDD seems to start with domain object model, and this seems very close to Information Viewpoint in RM-ODP.  What is RM-ODP Enterprise Viewpoint equivalent in DDD?  How is e.g. activity (process) dealt or modeled within DDD?

3) If DDD starts with Information Viewpoint (without Enterprise Viewpoint), and if the implementation is based on the domain model, then it seems Computational Viewpoint equivalent is very close to Information Viewpoint object model, which is distribution transparent and thus requires Engineering Viewpoint and Technology Viewpoint to specify implementation and deployment model (using informal terms).  

Any suggestions/comments?

WODPEC 2008 Proceedings available online!

The proceedings of 5th International Workshop on ODP for Enterprise Computing (WODPEC 2008) is available online at this page.

Renewal of RM-ODP Resource site

For your information on renewed RM-ODP Resources Site:

• Take a look at renewed RM-ODP Resource site or RM-ODP Wiki.
• Try UML for ODP data in ODP Resouces section of the above site. You can find several sets of UML Profile data for RM-ODP. Also, contributions are welcome to that section.

SOA, BPM, and RM-ODP

Discussion place for SOA, BPM, and their positioning within RM-ODP

There are discussions regarding the relationship between “service” in SOA and “process” in BPM. One view is that a process comes first as a way of achieving specified goal of an enterprise defined in business modeling, and the process is refined into steps (step could be a process defined elsewhere), and services need to be prepared to support steps and the process. In this view, process comes first. In another view, business modeling is to define a set of business services and the collaborations (or interactions) between them. In this view, a process is a way to implement a business service. My take is both are reasonble approach, and the difference is just a viewpoint taken by the specifier or modeler or designer. It may be a good idea to introduce “service view” and “process view” in enterprise or business modeling. They are different approach but I think eventually they define the same aspect of the target system specification.

In RM-ODP, we have process concept mainly defined and used in enterprise language and enterprise specifications. So it may be natural to say RM-ODP takes process approach. However, if you consider a set of comunity objects working together to achieve some objectives, or if you consider a set of roles whose behaviour includes interactions between them, they can be considered as models or specifications based on service first approach, although a term service is not used here.

We just need a clear understanding of the relationship and/or positioning of process and service in RM-ODP or in Enterprise Architecture.

Non-functional requirements and RM-ODP

Discussion place for the relationship between non-functional requirements and RM-ODP.

For instance, in which viewpoint do you claim something as non-functional requirements? Usually it is enterprise viewpoint, right? The things called non-functional requirements are only non-functional in terms of enterprise viewpoint. If you think about security or reliability (by replication), to name two of them, RM-ODP provides ODP functions like several kinds of security functions and replication function. With the help of those functions, you can express e.g. security related non-functional requirements in enterprise viewpoint as something functional in your computational and/or engineering viewpoint specifications. They are only non-functional when referred in enterprise viewpoint. Is this always the case? Is there any good way to express non-functional requirements in RM-ODP or UML4ODP models? Is RM-ODP policy the right tool for this job?

Also, someone said that non-functional requirements may exist in every viewpoint. Do you agree with this claim?

Reference:

• Wikipedia’s entry of Non-functional requirements
• RM-ODP Policy concepts

How to find RM-ODP related resources on the web

This post is just informational.

RM-ODP stands for Reference Model for Open Distributed Processing, but sometimes people call it differently.  The following is a list of [non-exhaustive] terms you may pass to search engines of your choice to find RM-ODP related URLs.  However, the best place to start is to go visit RM-ODP Resource Site (for URL, see the welcome message of this blog).

• RM-ODP
• RMODP
• RM_ODP
• ODP-RM
• ODP
• Open Distributed Processing
• SC21/WG7

Methodology and RM-ODP

Disccussion place for methodology for RM-ODP

RM-ODP is designed as notation and method free, meaning any notation can be used and any method for developing viewpoint specifications can be used. Regarding notation, the standard body has worked to developUML4ODP (it is final draft international standard now). However, there is still no standard way of developing ODP viewpoint specifications. Ideally, you can start developing ODP specifications from any one of the five viewpoints, but it may be useful to have one or two or three reference methods so that people can develop their own or customize it to meet their needs. Viewpoint concept in RM-ODP is similar with perspective concepts in Enterprise Architecture (EA), and TOGAF (THE OPEN GROUP’s Application Framework) contains an example method for EA So why not creating something for RM-ODP?

Your comments will be appreciated.

Reference:

• Wikipedia’s entry of TOGAF

Virtualization and RM-ODP

Discussion place for the relationship between virtualization and RM-ODP.

For instance, existing various server virtualization technologies make Engineering specification difficult to express, since it is not clear if “hypervisor” is positioned as Nucleus or as a part of Nucleus or … If it is Nucleus, then how can we position hosted operating systems? There may be other kind of virtualization too. What is your take on this?

Reference:

• RM-ODP Engineering language
• Wikipedia’s entry of Virtualization

Businss Rules and RM-ODP

Discussion place for the relationship between business rules and RM-ODP.

For instance, what is the relationship between (business) rules and policies of RM-ODP? If business rules are to be incorporated in Enterprise specifications, how should they be represented with text and with UML and … ?

Reference:

• RM-ODP Policy concepts
• Wikipedia’s entry of Semantics of Business Vocabulary and Business Rules

Business Modeling and RM-ODP

Discussion place for the relationship beween business modeling in general and RM-ODP.

For instance, Enterprise Language of RM-ODP can be considered as its version of business modeling. However, there are many more standards from OMG, such as Business Motivation Model (BMM), Semantics of Business Vocabulary and Business Rules (SBVR), as well as Business Process Definition Metamodel (BPDM) and Business Process Modeling Notation (BPMN) etc. How do we want RM-ODP to deal with those standards?

Reference:

• Wikipedia’s entry of Business Motivation Model (BMM)
• Wikipedia’s entry of Semantics of Business Vocabulary and Rules (SBVR)
• Wikipedia’s entry of Business Process Definition Metamodel (BPDM)
• Wikipedia’s entry of Business Process Modeling Notation (BPMN)