Using Causal Loop Diagrams (CLDs)

Hi there

Find attached a "report" I wrote for a fictitious company in which the primary modelling tool was Causal Loop Diagrams (CLDs). This was an interesting experience as part of some broader study on soft systems methods.

http://www.chriskempster.com/data/ChrisKempster_Assig1_CSI5202_v4.doc


Cheers


Ck

Google Calendar

I am sure most are aware of Google Calendar right? if you are not, then take my advise, take the time to have a good look. Create a google account (you can use your existing private email address, you don't need to use gmail) and navigate to the calendar.

The key feature here is the fact you can "subscribe" to 'other calendars', performing googles famous text search for events in your local area - in my case Perth, and locking this it to highlight all the activities running throughout the week, and more importantly for my young family, the weekend!



The screen shot above is an example. From here I can very quickly plot out a weekend of cheap and fun activities for the kids.

Combined with google maps, google calendar is a fantastic example of simple to use, fast and accessible social computing services.

Database Server – Service Tiers

The diagram below provides an overview of a consolidated enterprise database-hosting platform.

The tiering allows multiple applications to share and also span a smaller number of highly available infrastructures. The provides numerous benefits, such as:

• Multiple classes of application can leverage previously unattainable high availability services at a lower (shared) cost;


• More efficient use of server capacity;


• Database licensing efficiencies;


• Reduced points of administration and management;


• Fewer but better skilled database administration staff; and


• Reduced physical infrastructure based on relatively inexpensive high performance server hardware with nominal rack space and power utilisation.

The requirement for dedicated hardware for an application based on vendor contractual limitations, should be avoided. Dedicated database hardware should only be used where the database platform is not strategic, and/or there are potential reliability or performance issues identified due to poor application design.

Unified Messaging - Quick Definition

As a definition, Unified or Integrated Messaging is regarded as the single presentation, control and management of multiple media based services as a unified service from an end users perspective.

This in part is achieved through a ubiquitous, secured and managed WAN and LAN IP network infrastructure.

Key attributes such as bandwidth, latency, security, pervasiveness and quality of service ensure that not only data, but voice, video, fax and other [semi]-rich media services can be converged and delivered whatever the device or location, wired or wireless. This is a fundamental basis for a successful unified messaging architecture.

Social Computing

The term social computing refers to the creation and management of social contexts through the use of software and supporting connected technologies.

From a software perspective, this includes:
· Blogs[1];
· Email;
· Realtime communications (i.e. IM, on demand web video conferencing etc);
· Wiki’s[2];
· Collaborative filtering[3] etc.

From an Enterprise perspective, much of what occurs within an internet setting can be repeated in an enterprise context, with social and networked modifications to company intranets (portal) and native “out of the box” interoperability with other communications platforms (e.g. integrating click to call on a users “my site” portal page, calendar events published with zero touch programming in a users portal blog, or a clinical community group portal with collaborative document sharing).

Conceptually this can be represented as shown below:

The Enterprise Portal is the foundation for an enterprise users “web-presence”, including the development of mashed-up [composite] applications. This provides the foundation for enterprise content management tools, enterprise search and other collaboration tools for information workers in a dynamic enterprise wide social network.

In context to Unified Messaging, social computing helps describe the social networking intent in which unified messaging technologies, as presented in this standard, can be leveraged.

[1] is a website where entries are written in chronological order and commonly displayed in reverse chronological order. Blogs provide commentary or news on a particular subject; some function as personal online diaries. A typical blog combines text, images, and links to other blogs, web pages, and other media related to its topic. The ability for readers to leave comments in an interactive format is an important part of many blogs.
[2] A wiki is a collaborative website which can be directly edited by anyone with access to it.
[3] A method of making automatic predictions (filtering) about the interests of a user by collecting taste information from many users (collaborating). The underlying assumption of CF approach is that those who agreed in the past tend to agree again in the future.

Soft System Methods - A Critique

Here is a paper I completed on Soft Systems Methods. This was another Master's study unit that I really enjoyed as it covered aspects of modelling that is typically found in Management units.

http://www.chriskempster.com/data/Soft%20Systems%20Critique%20v7.doc

The paper covers three methods:
1) Soft Systems Methodology (SSM);
2) Strategic Options Development Analysis (SODA); and
3) Socio-Technical Analysis (STA).

I have applied each method to a small case study of which you will get a gist of in the paper. If you would like a copy of the case study then please email me (ckempste@iinet.net.au).

Each method observation includes industry and academic views to support or negate the author’s perceptions, and assist in the location of patterns in which to summarise each methods critique.

The analysis will also build the readers perception of the picture shown in the diagram below, suggesting that any sufficiently complex requirement will require the adoption of a multiple methods.

Agile Architectual Modelling

Scott W.Ambler is an interesting cowboy hat-wearing architect that has penned a large number of books covering application development agility, including agile modelling:

http://www.agilemodeling.com/essays/agileArchitecture.htm

Scott is the founder of Agile Unified Process (AUP), an interesting and pragmatic look at RUP and well worth the read if you are considering agile development processes/frameworks. I also recommend his Yahoo Groups page / email list which Scott actively partakes in (rather than other lackey)...

http://groups.yahoo.com/group/agileUP/

Technical Infrastructure Design Patterns

Hi there. I have long been an advocate of infrastructure patterns (or blueprints). They have been around for a while and covered by a range of well known authors, but funny enough I struggle to find technical architects that talk to them, both technically and with the client.

The infrastructure blueprints provide the high level implementation framework for a solution on which vendor software is applied [and the patterns possibly altered]. The framework can state minimums across application service tiers, i.e. a class one application may using pattern X and storage pattern Y in order to achieve the required availability; and form the basis of enterprise standards on which specific vendor software platforms (further standards) apply.

The patterns can also provide a road map for change, allowing complex technical implementations to be boxed as logical concepts whose change over time can be articulated with the business and their respective clients. As with any change, infrastructure and software pattern changes also drives capability maturity - the possible need to invest in skills to sustain the stability and benefits of the pattern in production.

The presentation is a little rushed; but not too disorganised :) comments welcome.

http://www.chriskempster.com/data/Technical%20Infrastructure%20Patterns.ppt

Observer Pattern - An Introduction

Here is a presentation covering the Observer GOF pattern I did some time ago.

http://www.chriskempster.com/data/Observer v3.ppt

SOA Anti-patterns

I completed a Master's study unit around 6 months ago on Design Patterns; this unit was particularly interesting in the fact that you could pick any topic you liked and research/analyse/deliver it depending on the learning experience you wanted to achieve. Of interest to me was the "dark side" of service orientated architecture, namely anti-patterns.

Rather than simply list a range of identified anti-patterns, the later part of the presentation asks the question - "are there patterns within the anti-patterns" ? the resounding answer is yes! with due planning and management you can not only sell the risks to management, but plan supporting policies and governance models to manage them.

Presentation can be found here http://www.chriskempster.com/data/Service Orientated Architecture (SOA) Patterns v2.ppt

Comments welcome.