Large 24 7 systems and agile soft dev - shanghai aha conference

Large 24 / 7 systems and
Agile Soft. Dev.
Old story, new story, tips

Viktor Grgic @vgrgic Odd-e Hong Kong Blog: leanarch.eu odd-e.com http://less.works
Gartner says…
• Bimodal IT is the future
- 2 distinct IT methodologies in the same
company
- “Agile IT” teams for fast-changing stuff
- “Traditional IT” for doing things right the ﬁrst
time.
2
Euhmm……No!

Large software projects
today
• ...are replacing something old for new.
• Many of them have single goal: Replace outdated
technology with new one.
• Many of them are huge investments with long
term promises of so called ﬂexibility in future.
• ...and if your large project is none of these, then
you’re maybe creating a christmas tree. 
Looks nice, but it is dead very soon.
• …or your project is small and delivers value
3

Some nice False Dichotomies
(fallacy of the false alternative)
4
“You can’t simply start coding, therefore you always
have some up-front design.”
“Developers don’t care and are incapable of caring about
architecture, because they need to focus on coding”
“Agile / Scrum, that is something for frontend apps, not
for 24/7 business critical systems”
We need to
be more Agile
We need more
architecture
“Some things cannot and should not change”

The biggest problem in software
architecture is that we think we know
what we are doing.
5

Large software projects today
7

Large software projects today
8

9
Great Mosque of Djenné, Mali ruins
1828

10
Great Mosque of Djenné rebuilt
1895

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Great Mosque of Djenné
1910

12

13

14

15

16

17

18
Everyone
is
involved

19

About 7 years ago...
20
Port of Rotterdam, Project HaMIS
1. Replace outdated traffic management system
2. Support the port of Rotterdam expansion
24/7 system for traffic management, transport,
environmental safety and crisis management.

New (as deﬁned about 6 years ago)
21

Lots of documents
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Migration
Plan
Architecture
Vision
Operations
Vision
....
QA
Vision
Blueprint
Reference
data
Vision

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100+
identified
use cases
Project Start
Architecture
Q&A
department
Architecture
with 4 layers &
6 subsystems
6
architects
800+
architectural
decisions
RUP and Scrum
but
BPEL
process
server
We just need...

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1 Use Case in 6
months

(Re)Started
• Ship inspections process
• Little risk
• Signiﬁcant business value
• Migration stuff completely postponed
• Agile / Scrum introduction
• One sprint later, useful functions delivered in
production
25

26

Optimize the whole
27
Marketing
User /
Business
Requirements
gathering
Architectu
re
Planning
Analysis
Development
TestingDelivering
...has a
challenge
Lead
time
Department 1 Department 2 Department 3
Department 4
Department 5
Department 6
Department 7
Department 8
Agile team
Agile team
Agile team
Agile team

Product Vision Box
28

Self-designed teams
29
See
LeSS.works
if you want
to know
more

Architecting
30
Open space
sessions
Knowledge
sharing
Documentation is Wiki
filled by “harvesting” the
knowledge
Standardization is
discovered and not
predefined
Just-in-time
just-enough
Continuous
refactoring towards
better design
Architecture principles:
Simplicity and design for change

Business processes?
31

Technical debt
32
So, did we paid this
debt back ???

Continuous Architecting
33

Things that matter
34
Multilayered Domain-
Driven
DesignSOA
SOAP
Frameworks
Micro-
services
Simplicity
Business-
driven
everything

What was my role?
35
Management:
”…but who is
accountable?”

Welcome to double legacy
36

Which path to choose?
• Should we do all reporting ﬁrst in the new
system?
• Which part of the system should we replace ﬁrst?
• How do we prevent a big bang?
• Where to start?
• We followed ships in harbour!
37

38
Any decision that can be
postponed is postponed
...also the migration path
…but, this is not easy

Migration = Strangulation
39
HaMIS (new)IVS (old)
User
Business
event 1
Business
event 1
Business
event 2
Business
event 2
data not yet managed in HaMIS
"The most important reason to consider a strangler application over a
cut-over rewrite is reduced risk.” - Martin Fowler, StranglerApplication
24/7 system Every 2 weeks
in production

We banned terms:
Generic or Reusable
on every level
40

We banned premature
generalisation
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Why Windows 10 instead 9 ???
“Microsoft dev here, the internal rumours are that
early testing revealed just how many third party
products that had code of the form
if(version.StartsWith("Windows 9")) { /
* 95 and 98 */ } else {
and that this was the pragmatic solution to avoid that.”

Aren’t you creating a mess?
• One team delivers the simplest possible solution
• Another team delivers another similar even
simpler possible solution :-)
• ...and maybe third one.
• Then, we get together and talk about what you
learned and which one is really the best in this
context.
42

Examples
• Data model with production data is gradually
extended and continually refactored
• IBM Websphere replaced by JBoss
• User interface redesigned 2 or more times
• SOAP replaced by binary Hessian
• Core domain model concepts (gradually)
redesigned: inspection checklist, vessel visit vs.
vessel
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Lessons learned
• Never stop delivering business value.
• Deal with migration gradually / strangulation
• Everything in software can be soft even data /
domain model!
• Trust in business / context driven approach above
standard / generic solutions
• Involve everyone to solve complex problems
• Don’t get stuck in complexities of architectural
B.S.
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6 years later
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Then
6 months delivery time for large
features
“Documents”-based collaboration
business / IT
Dedicated operations team - 6
people + on average 5 developers
fixing issues full time
Many architects, analysts, QA,
“coordinators”
Very displeased business
Now
More than 100 sprints every 2 weeks
new features / intensive
collaboration
No dedicated operations team
Production issues involving code
change solved in 1 hour!
One of 4 development teams
responsible for operations, 30% of
time actually spend on operations.
Architects, analysts, QA, OPs,… part
of cross-functional teams

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“Everybody, all together, early on”
James O. Coplien

Want to know more?:
less.works
Blog: leanarch.eu
Tomorrow:
Collaborative Visualisation
workshop
47

Large 24 7 systems and agile soft dev - shanghai aha conference

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Large 24 7 systems and agile soft dev - shanghai aha conference