How Should We Use “System of Systems”

… And Why Should We Care?

Dan CocksLockheed Martin - MS2

July, 2006

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Context:

• Systems Engineering (SE) is a relatively new engineering discipline

• SE is characterized by a disciplined process that can be applied across a variety of problems– Telephony (early 1900s)– Missile defense (~1940s)– Software-intensive systems (~1970s)

• Premise: In order for the term “System of Systems Engineering” (SoSE) to have meaning apart from SE, there must be meaningful differences in their respective processes

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Introduction:

• You have recently been asked to lead a Systems Engineering (SE) development project.

• At your first meeting, you have learned that it is actually a System of Systems (SoS) project.

• What does that change for you?– Additional engineering steps for your team?– Different milestones? – Different types of risks?– Different skill mix needed to staff the team?

• Does it tell you anything for sure?

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Common SoS Characteristics:

System of Systems:•operational independence of individual

systems •managerial independence of the systems •geographical distribution•emergent behavior •evolutionary development

Many SoS definitions & characterizations look like a result of whiteboard brainstorming of lots of ideas of what systems of systems often look like.

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Common Characteristics are not Always Distinguishing Characteristics

• SoS does not always mean “geographically dispersed” – some systems (not SoS) are dispersed

• A SoS may not always display emergent behavior – many systems (not SoS) have emergent

behavior)

• Many fast cars are red– Color does not make them fast

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SE vs. SoSE

• In order to have SoS Engineering (SoSE) that is distinct from SE, we must identify:– A boundary that clearly segregates

SE and SoS projects and/or systems so we can tell them apart.

– Engineering steps or other characteristics that apply to one and not both engineering projects so we know why we need to tell them apart.

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What’s in a Name?

• What makes Ketchup “Fancy”?– More vinegar & spice?– More sugar?– More preservatives?

• Is “Fancy” used to convey meaning, or just to impress?

Pictures courtesy of “The Original Condiment Packet Museum” www.clearfour.com/condiment/

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Is SoSE just “Fancy SE”?

• Does SoSE convey meaning,– Different life cycle– Different development/sustainment processes– Different development/sustainment staffing needs

• Or is the term used more to impress than to inform?– Bigger– Harder– More complex in some unspecified number of ways

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SoSE is not Bottoms-up Engineering

Some see:• Systems Engineering (SE) as

top-down solutions to a known mission or problem

• SoSE as a bottom-up discovery of new problems that can be solved using existing systems in new ways.– Hence, a “Lego® problem”: “What

can I build from these?”

Pictures from www.Lego.com

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A Postulated Definition for SoS:

A system of systems is a product of a system engineering process that contains one or more systems for which significant aspects of the integration and life cycle development of the component system(s) are beyond the managerial control or influence of the larger system.

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Is it SE, SoSE, or FoSE*?

Starts with Mission?

Responsible for consequences

of integrating?

Identify system requirements & select solution architecture

Solution contains > 1 independent

system ?

If solution does not

fully satisfy requirements

Not Systems Engineering

Systems Engineering

No

Yes

Yes

No

Design new interfaces and “wrapper” solutions

to integrate systems

Adjust requirements to match existing

systems

System of Systems

Engineering

Family of Systems

Engineering

Modify existing system(s)

Yes

No

*FoSE = “Family of Systems Engineering”

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Is the SoSE Process Different than an SE Process?

• SoSE is part of SE, so there are no process steps that are unique to SoSE

• SoSE is a particular type of SE:– Trade studies may be fewer because large chunks of

functionality are already provided in legacy systems– Risks may be greater since legacy systems have

managerial independence– Development staffing, schedules, & budgets should be

adjusted to reflect these differences

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Summary

• SoSE is not a meaningful term – The engineering processes for a SoS are the same as

SE processes for any other system

• SoS is a sub-category of systems for which component parts are systems with managerial independence– SoS programs have common risks and attributes so the

balance of SE steps tend to be similar– Programs can benefit from recognizing a SoS and

planning accordingly

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Back-up (to Ketchup)

• Someone actually paid $7.00 to Google Answers to get about a page of research that concluded:– “It would appear that the use of ‘Fancy’, as with

many other packaging notations, is merely a marketing ploy to try to convince the consumer that one brand of seasoned tomato glop is better than another.”