Workflow SystemsMyths, Truths and Wishful ThinkingBrandon SatromChief Architect, Thought Ascentbrandon.satrom@thoughtascent.comwww.userinexperience.com

Copyright 2009, Thought Ascent, IncAbout Me - In Six WordsOpinionated Architect. Often wrong. Continually improving.

Long-time Microsoft developerFormer Enterprise ArchitectAlt.Net guy, but still nicePresident, IASA AustinCopyright 2009, Thought Ascent, IncWorth mentioning?

Experience with vendor WF toolsExperience with BizTalk (2002+)Recently built a successful production implementation using WF 3.5See that “opinionated architect” comment.Copyright 2009, Thought Ascent, IncWhat qualifies me to talk about Workflow…

Copyright 2009, Thought Ascent, IncSo what is “Workflow” anyway?

Copyright 2009, Thought Ascent, IncA workflow is a depiction of a sequence of operations, declared as work of a person, a group of persons, an organization of staff, or one or more simple or complex mechanisms. Workflow may be seen as any abstraction of real work, segregated in workshare, work split or other types of ordering. For control purposes, workflow may be a view on real work under a chosen aspect, thus serving as a virtual representation of actual work. The flow being described often refers to a document that is being transferred from one step to another. – from http://en.wikipedia.org/wiki/Workflow

Copyright 2009, Thought Ascent, IncHow about something simpler?

The coordination of work in a “system”Copyright 2009, Thought Ascent, Inc

Copyright 2009, Thought Ascent, IncGot it. So then what’s a “Workflow System?”

Perhaps…An application that assists in the definition and/or execution and/or management of workflowsCopyright 2009, Thought Ascent, Inc

Copyright 2009, Thought Ascent, IncThat sounds too similar to a “normal” system. What’s the difference?

How a workflow system differs from a traditional programIn theory, at least…Copyright 2009, Thought Ascent, Inc

DeclarativeCopyright 2009, Thought Ascent, Inc

PersistentCopyright 2009, Thought Ascent, IncExternal StimulusPersistence Store

DynamicCopyright 2009, Thought Ascent, IncBusiness ChangeActivity FDivert to new activity

ConfigurableCopyright 2009, Thought Ascent, IncActivity DActivity ERules Store

Centrally Defined…Copyright 2009, Thought Ascent, Inc

… though not necessarily visual.Copyright 2009, Thought Ascent, Incstatic SessionSaga(){ Define(() => { Initially( When(NewSession) .Then((saga, message) => saga.NewSessionStarted(message)) .TransitionTo(SessionActive) ); During(SessionActive, When(FeedbackCheckRequested) .Then((saga, message) => saga.CheckForFeedback(message)) When(new Timer() .StartOn(session.Start) .RunAtInterval(session.CheckInterval) .Until(session.End)) .Then((saga, message) => saga.CheckForFeedback(message)) When(SessionComplete) .Then((saga, message) => saga.SessionEnded(message)) .Complete() ); });}

Copyright 2009, Thought Ascent, IncOk, I get it. So why are we still doing this presentation?

Copyright 2009, Thought Ascent, IncWorkflow has a PR problem…

Copyright 2009, Thought Ascent, IncThere seem to be two sides…

Copyright 2009, Thought Ascent, Inc…who can’t (or won’t) get along.

The “Workflow will Save us all” sideCopyright 2009, Thought Ascent, Inc

The “Run like you’re on fire” sideCopyright 2009, Thought Ascent, Inc

Copyright 2009, Thought Ascent, IncI’d like a third option please.

Copyright 2009, Thought Ascent, IncHow about the best of both?

Consider both sides of the story…

And be a cautious optimist…Copyright 2009, Thought Ascent, Inc

There are reasons to get excited about Workflow…Copyright 2009, Thought Ascent, Inc

Copyright 2009, Thought Ascent, IncVisual, Visual, Visual

Copyright 2009, Thought Ascent, IncClear expression of intent from domain experts…

Copyright 2009, Thought Ascent, IncThe Next “Great Leap” in software

…and there are reasons to be wary…Copyright 2009, Thought Ascent, Inc

Steep-learning curvesCopyright 2009, Thought Ascent, Inc

Copyright 2009, Thought Ascent, IncPoor Performance

Copyright 2009, Thought Ascent, IncSleights of hand and shell-games

Copyright 2009, Thought Ascent, IncBoth sides are right …Both sides are wrong….

Copyright 2009, Thought Ascent, IncRight and wrong? How so?

Myths, Truths and Wishful ThinkingCopyright 2009, Thought Ascent, Inc

1) Visual Workflow Tools are the only way to “do” WorkflowCopyright 2009, Thought Ascent, Inc

MythCopyright 2009, Thought Ascent, Inc

Is this really easier to comprehend…Copyright 2009, Thought Ascent, Inc

Than this?require 'rubygems' require 'statemachine' vending_machine = Statemachine.build do state :waiting do event :dollar, :paid, :activate event :selection, :waiting on_entry :sales_modeon_exit :operation_mode end trans :paid, :selection, :waiting, :release trans :paid, :dollar, :paid, :refund context VendingMachineContext.newendCopyright 2009, Thought Ascent, Inc

The TruthMany open-source “code-first” solutions offer most of the benefits of a workflow system without the steep learning curve.Copyright 2009, Thought Ascent, Inc

Demo –Workflow with Mass TransitCopyright 2009, Thought Ascent, Inc

2) Workflow should be running all your application logicCopyright 2009, Thought Ascent, Inc

LieCopyright 2009, Thought Ascent, Inc

Turn a simple flow…Copyright 2009, Thought Ascent, Inc

…into “Spaghetti Flow”Copyright 2009, Thought Ascent, Inc

The TruthWorkflow systems can be a good choice for managing long-running, complex processes, but don’t yet perform well-enough to handle all your logic.Copyright 2009, Thought Ascent, Inc

3) Domain experts can (and should) easily change workflows at runtimeCopyright 2009, Thought Ascent, Inc

Copyright 2009, Thought Ascent, Inc

Wishful Thinking…Copyright 2009, Thought Ascent, Inc

The TruthWe don’t change systems at runtime without some diligence. So why would our users? That said. There are models that are more illustrative of reality…Copyright 2009, Thought Ascent, Inc

4) Declarative/Visual App Dev is easier than traditional dev…Copyright 2009, Thought Ascent, Inc

Half-TruthCopyright 2009, Thought Ascent, Inc

The TruthWhere it’s easier:OOB programming constructs (IF, While, etc)Encourages/ Rewards SRP-developmentWhere it’s harder:Visual IDEs slower than code IDEsTesting is hard, if not impossibleRefactoring involves more rework than necessaryCopyright 2009, Thought Ascent, Inc

5) “I can build a WF system in 100 lines of code”Copyright 2009, Thought Ascent, Inc

Wishful Thinking…Copyright 2009, Thought Ascent, Inc

The TruthCode-only solutions can address simple scenarios quickly…But tend to unravel when persistence, durability, scale,timed-events, long-running processes, human workflow and other complex issues are introduced.Copyright 2009, Thought Ascent, Inc

The Faceplant Application“Social Speaking”Demo:Copyright 2009, Thought Ascent, Inc

Copyright 2009, Thought Ascent, IncCongratulations! You’ve done an excellent job of not telling me what I should do…

Open Discussion – When should a Workflow Tool be considered?Copyright 2009, Thought Ascent, Inc

When does WF make sense?…Copyright 2009, Thought Ascent, Inc

Copyright 2009, Thought Ascent, IncI think it’s time for the bottom line…

There is no simple answer…Only the right tool for the jobCopyright 2009, Thought Ascent, Inc

The Right Tool for The Job might be…“Roll Your Own” WorkflowUse an open-source BusNServiceBusMass TransitSimple ServiceBusUse an open-source State management toolSimple State MachineUse Windows WFAfter you’ve exhausted all other possibilitiesCopyright 2009, Thought Ascent, Inc

Consider a “Workflow System” when:Need a visual, changeable representationTimed-events are keyLong-running:TransactionsConversations ServicesMany, complex processes Economies of scale principleCopyright 2009, Thought Ascent, Inc

Don’t start with a workflow system as a solution.Get there by eliminating other optionsCopyright 2009, Thought Ascent, Inc

And pay attention…Software development is changing.Copyright 2009, Thought Ascent, Inc

Questions?brandon.satrom@thoughtascent.comwww.userinexperience.comTwitter: @thesatchCode and slides available at: http://github.com/bsatrom/WorkflowSystemsCopyright 2009, Thought Ascent, Inc

Image CreditsWF System, InfoWorldhttp://www.infoworld.com/d/developer-world/product-review-ultimus-jump-starts-bpm-deployment-546?page=0,1Pinnochio – House of Sims, Flickrhttp://www.flickr.com/photos/houseofsims/2662410465/Myth – Mythbusters on Discoveryhttp://dsc.discovery.com/fansites/mythbusters/wallpaper/wallpaper.htmlSteep Learning Curve – Casual Game Designhttp://www.casualgamedesign.com/?p=27Skeptic Guy – Flickhttp://www.flickr.com/photos/mcleod/3909431214/in/set-72157607796029636Copyright 2009, Thought Ascent, Inc