Why Enterprise Architecture Usually Sucks.

Why Enterprise Architecture Usually Sucks.

Phillip CalçadoThoughtWorks

http://fragmental.tw

Saturday, 11 September 2010

1.Conway-Driven Architecture2.Architecture-Driven Business


1. Conway-Driven Architecture

“Any organisation that designs a system will inevitably produce a design whose structure is a copy of the organisation's communication structure.”

-Melvin Conway


team a

team b

team b

team c


team b

systema

systemb

systemc


team b

systema

systemb

systemc

doesn’ttrust

doesn’ttrust

doesn’ttrust


team b

systema

systemb

systemclegacy

database x

billing system y

inventory system z

hrsystem w

portal s


can I have this feature?

pretty please?


LOL r u crazy?


team b

systema

systemb

systemclegacy

database x

billing system y

inventory system z

hrsystem w

portal s

This “small” change means...


team b

systema

systemb

systemclegacy

database x

billing system y

inventory system z

hrsystem w

portal s


change


team b

systema

systemb

systemclegacy

database x

billing system y

inventory system z

hrsystem w

portal s


change

change


team b

systema

systemb

systemclegacy

database x

billing system y

inventory system z

hrsystem w

portal s


changechange

change


team b

systema

systemb

systemclegacy

database x

billing system y

inventory system z

hrsystem w

portal s


changechange

change

change


team b

systema

systemb

systemclegacy

database x

billing system y

inventory system z

hrsystem w

portal s


changechange

change

change

change


team b

systema

systemb

systemclegacy

database x

billing system y

inventory system z

hrsystem w

portal s


changechange

change

change

change

change


“I don’t understand why things are so hard around here!”“IT doesn’t deliver; we need more people. Get me some consultants!”“In-house is too complicated, let’s buy a package!”

“We are too slow. We have to become agile! ”


2. Architecture-Driven Business

“Developers have to translate for domain experts. Domain experts translate between developers and still other experts. Developers even translate for each other. The indirectness of communication conceals the formation of schisms. This leads to unreliable software that doesn't fit together.”

-Eric EvansSaturday, 11 September 2010

IT always wins.


IT always wins.

We need invoices to be available in our

sales channel to our customers


IT always wins.

We need invoice.xsds to be available in our portlets to our

contacts


developer’s kingdom

business’ nightmare


developer’sbusiness’

InvoicingOracle Invoice Server + PDF Printing Service + SAP

CustomerIdentity Manager + CUS_SYS_01 Database + CRM

SaleCMS + E-Commerce Server + Warehouse System

mapping


“How did we end up with three CRMs again?”

“These customers are in another database. We can create a service

for that...”

“This may be a simple change for the business but in our end it’s complicated!”Saturday, 11 September 2010

Some Suggestions


1.Don’t try to break the law2.Design principles are fractal3.Domain-Driven Architecture


team b

systema

systemb

systemc


team b

systema

systemb

systemc

the governance group


team b

systema

systemb

systemc

the governance group bottleneck


createoneproject team

withpeople

from different departments


team b

systema

systemb

systemclegacy

database x

billing system y

inventory system z

hrsystem w

portal s


OperationOperation

AttributeAttribute

OperationOperation

AttributeAttribute

OperationOperation

AttributeAttribute

OperationOperation

AttributeAttribute

OperationOperation

AttributeAttribute

OperationOperation

AttributeAttribute

OperationOperation

AttributeAttribute

team b

system a

system b

system c

legacy database

x

billing system y

inventory system z

hr system w

portal s


•Layers•Cohesion•Coupling•Dependency Injection•...

still applies


big bangmapping


Adopt Layers

BusinessServices

}}

InfrastructureServices


Adopt Layers

InfrastructureServices

BusinessServices

}}

TechnicalVocabulary

(and no Business Logic)

BusinessVocabulary

(and Business Logic)


Adopt Layers

littlemapping


Good Architectures support and are driven by the business

Bad Architectures require the business to change

What’s easy to change in the business model should be easy to change in your

architecture


References•http://www.melconway.com/research/committees.html

•http://fragmental.tw/2009/02/24/what-is-a-service/

•http://fragmental.tw/2010/08/17/thoughts-on-abstractions-part-1-%E2%80%93-abstractions-everywhere/

•http://fragmental.tw/2010/09/06/thoughts-on-abstractions-part-2-abstractions-in-your-domain/

•http://fragmental.tw/2010/03/22/nevermind-domain-driven-design/


http://fragmental.tw/2009/02/24/what-is-a-service/






















Why Enterprise Architecture Usually Sucks.

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Transcript of Why Enterprise Architecture Usually Sucks.