Architecting in a Complex System Environment

John Hodgson & Phil PiperICT Architects

The fundamentals of Complex IT System/s(Using Government systems examples)

Complex IT systems What is a complex IT system? Common Factors and Influences (within a Government environment).

A Systems of Systems view Common Factors

Value and issues in identifying, analysing, designing and specifying IT systems in a complex environment.

Architecture Frameworks Models and Zachman, DODAF, MODAF, AUSDAF and TOGAF Gordian

knot. Business, Systems, Services and Technology

Complex System Architect’s basic tool sets Whiteboards, A3 sheets, Office, Visio, JPGs, System Architect, etc.

Useful approaches to understanding Complex Systems. Useful approaches  to Architecting Systems in a complex

environment.

Complex I.T. systems What is a complex IT system?

More than three subsystems.. Multiple business process engagement Significant data exchanges Significant human interactions within the

systems How do you recognise this?

Different governance regimes evident High frequency of change Multiple data exchange methods Complexity behaviours

An Alternate View of Complexity What is a complex IT system?

A complex system is one that exhibits emergent behaviour.

Emergent Behaviour is behaviour that was not predicted from the sum of the functions of the parts.

For example, the World Wide Web is a “small-world network”. Ie, the number of hops between two nodes increases in proportion to the log of the number of nodes. That was not “designed-in” or predicted by the designers.

Emergent behaviour is often negative. We call this “bugs”.

So, system collections are complex when they start exhibiting bugs that are the result of interactions between the systems. These can be very difficult to diagnose.

Dept of Defence

Dept of Defence(same information)

Defence – ERP Interfaces

Interfaces – How Many Are There?

2N > N(N-1)

How can that be?For N systems, the worst case is N(N-1)What we would like is at most, 2N

We can evolve a complex set of systems towards 2N by applying enterprise architecture patterns like SOA.

Systems of Systems

Complex systems are typically system of systems

Multiple layers of systems Architects are often tasked with only

a subset of this – Focus

Common Factors

Teaming is a necessity No single source of truth Fragmentation of design, projects and

support Documentation is always poor Abstraction is essential Architects become valued as

complexity increases

Complex Systems are influenced by many factors

e.g. Defence Warehouse Mobile Environment

Architecture Frameworks

Framework v’s Architectural process TOGAF ZACHMAN DODAF, MODAF and AUSTDAF

“Common language” for architects Rarely exactly accurate Most can be correlate to each other

Zachman (Circa 1990)

TOGAF(Open Systems Group)

DODAF V2

MODAF

AUSDAF

Basic tool sets for complex system architect’s Whiteboarding

Print copies, photos, coloured pens Integrated project teams, working groups,

team reviews A3 sketch pads MS Office, Adobe Acrobat Visio and JPGs System Architect & Enterprise Architect Above all, an inquisitive mind and some

affront to ask questions

External Imposed Policies & controls

Technical and Threat Risk Assessment

Assessment Processes Risk Sources

•Detailed Identified Risk Calculations(Add/Remove Information where required along with Risk Forms. Comments can be made in any field to enhance or better explain the rating.)

Risk Calculation Form Risk ID: R01

Threat Loss of services due to loss of communications (Example Only)

Threat sources TS16, TS17, TS19, TS20, TS21

Asset(s) Affected A1, A2, A6 A9, A30

Overview (insert comments here)The loss of the (System/Project Name) services due the infrastructure and networking outside the control of Defence being damaged or wrongly configured.

Likelihood of Occurrence (insert historical supporting information here)Possible

Consequence of Realisation (insert any supporting consequential comments here)Severe

Current Resultant Risk Exposure (insert further specific comments here)High

Treatment Option(Accept, Reduce, Avoid, Share)

Reduce

Treatment Recommendation(s) / Plan(s) TP01, TP02

New Likelihood of Occurrence (insert supporting future outlook comments here)Very Rare

New Consequence of Realisation (insert comments that may support the lowering of consequence, if justified)Severe

New Resultant Risk Exposure (insert any comments here such as countermeasure accompanied by treatment plan allowing the previous rating to be lowered)Medium

Table R01 – Loss of services due to loss of communications

Threat / Technical Risk Assessments (Aust / ISO Standards)

Useful approaches to understanding Complex Systems Start at the top - the Enterprise’s Business Objectives

Document visually and ask for comments Identify the Executive’s direction of change Document (or find) the objectives Identify the Enterprise “modus operandi”

Develop (or find) an outline Concept of Operations (or Concept of Business) How should the business be working?

How is it actually working? Strategic, Tactical and Immediate objectives

Lean from those who have gone before Look for historic and previous efforts Ask for the war stories, but don’t accept as gospel Where have the greatest changes occurred so far in the Enterprise? Why?

Look for “change levers” Small investments - large impacts

Be patient Enterprises take time to change

Both human and external factors rarely allow for “Engineering Discipline” But it doesn’t hurt to bring some skills to bear.

Draw and Write for your audience Who reads the Plumbing Specs for a new Building?

Prof Julius Somner-Miller (circa 1970s) Always ask - WHY is it so?”

Time for Questions

And thanks for listening…