software product lines

[email protected] @miles_no

software product lines

aka:

product line architecture

product family engineering

...


why


your problem to solve:

design the solution architecture for standardised case

management for all employment and social security

benefts in Norway (26 → 40 benefts)

Enterprise Architect: “They all follow the same

business process!”

Domain Expert: “They are all diferent!”

Case Handlers: “They all have to look for the same to

us!”


“On the design and

development of

Program Families”

- Parnas, 1976

Alternatives:

- Reference Architecture

- One-size-fts-all

- Software Product Line


core problem:

must understand the nature of variability in your

problem domain

Structural (Essential)

inherent in the problem domain- business wants to offer a set of products- product differentiation is a competitive advantage

Incidental(Accidental)

purely technical- technical debt- different development teams- etc


alternative 1: reference architecture

common logical architecture for all products

separate product instances in production

reuse of knowledge

opportunistic reuse of components

no explicit variation management

SU

SP

FP


alternative 2: one-size-fits-all

one physical architecture for all products

single product instance in production

complex variation management

significant reuse of components

difficult to deal with variation in quality requirements

regression testing for all products for all changes

SU SP FP


alternative 3: software product lines



reuse of knowledge

explicit variation management: functional and quality requirements

explicit reuse of components

requires more architecture investment

FP

SU

Felles


what


Domain Engineering

Application Engineering


how


BDUF or agile software product lines?


how


variation points in the architecture

For our case management domain:

variation in process

variation in domain model

variation in presentation

variation in legislation

variation in integration with external actors


variation guide

. doma in mode l . rule templates

. java component integration . service level integration


. selling the business case

. getting product owner(s) / domain experts to think

across products

. project organisation structure for common

components and product development

. how do you defne user stories and other

requirements?

. how much upfront design?

. SPL for enterprisey software rather than

embedded systems

Jones, Lawrence G ., and Linda M . Northrop. 2010. “Clearing the Way for Software Product Line Success.” IEEE Software 27 (3) (June).


summary

. is variation inherent to the business domain?

. are there enough products to justify payof with a

product line approach?

. analyse the variation

. design the architecture wrt commonalities and

variations

. develop a variation guide for combining common

assets and product-specifc variants

. don't forget the non-architecture challenges


more info

http://www.sei.cmu.edu/productlines/tools/framework/

● slides and images liberally stolen reused from

http://www.sei.cmu.edu/library/assets/spl-essentials.pdf

http://splc.net



http://splc.net/



http://splc.net/


software product lines

aka:product line architecture

product family engineering

...

* will talk about product lines* illustrate concepts with the modernisation of case management at NAV


why

* start with the why and compare it to other techniques* then look at what is a SPL * and then how we have been going about it


your problem to solve:

design the solution architecture for standardised case

management for all employment and social security

benefts in Norway (26 → 40 benefts)

Enterprise Architect: “They all follow the same

business process!”

Domain Expert: “They are all diferent!”

Case Handlers: “They all have to look for the same to

us!”

* how do you design the architecture for a while set of solutions?* all the solutions have many things in common but there is considerable variability* nobody is too sure what that variability is, nor what can be standardised


“On the design and

development of

Program Families”

- Parnas, 1976

Alternatives:

- Reference Architecture

- One-size-fts-all

- Software Product Line

* lots of research and industry experience on dealing with variability in software architecture* long history of dealing with Product Families* variations in functionality* variations in support for quality requirements* all that background shows three main alternatives


core problem:

must understand the nature of variability in your

problem domain

Structural (Essential)

inherent in the problem domain- business wants to offer a set of products- product differentiation is a competitive advantage

Incidental(Accidental)

purely technical- technical debt- different development teams- etc

* before you can analyse which alternative is relevant for you, you need to understand the nature of variation* Is it Essential or Accidental?


alternative 1: reference architecture



reuse of knowledge

opportunistic reuse of components

no explicit variation management

SU

SP

FP

*


alternative 2: one-size-fits-all

one physical architecture for all products

single product instance in production

complex variation management

significant reuse of components

difficult to deal with variation in quality requirements

regression testing for all products for all changes

SU SP FP

*


alternative 3: software product lines



reuse of knowledge

explicit variation management: functional and quality requirements

explicit reuse of components

requires more architecture investment

FP

SU

Felles

*


* summary.* notice when and how you explicitly handle variation (or not at all)


what

* all about product lines in general*


* all about product lines in general* architecture astronaut definition but there are actually many that use it successfully in practice** Nokia** GM car software** etc


* variation in software products directly linked to business case that can be build a business model around products.* easy in the embedded domain but not as common in the enterprise domain


* long term goal is to achieve this* not necessarily how you start* can't forget the management and organisation


Domain Engineering

Application Engineering

* core asset development = domain engineering* product development based on assets = application engineering


* not just component reuse* all the artefacts in the dev lifecycle


* requires architecture investment and you wont get the payback on the first system* There are alternatives. Ex: huge developer base in india


how

* variation analysis* variation points in the architecture* variation guide to describe how to deal with the variations in technology


how

* Need to consider the approach from two dimensions:** product, process and organisation** setting the context, getting started, working long-term


how

* example activities you can do in all these areas.** we looked at each of these to understand the ones that were the most relevant and pressing


BDUF or agile software product lines?

* Do you have to do all this upfront?* we started reactive but are moving to more incremental.** focus on analysis on variation rather than building components


how

* variation analysis* variation points in the architecture* variation guide to describe how to deal with the variations in technology


variation points in the architecture

For our case management domain:

variation in process

variation in domain model

variation in presentation

variation in legislation

variation in integration with external actors

* domain analysis to find the commonalities and variations* feature models are a popular technique* what we have been focussing on in case management


variation guide

. domain model . rule templates

. java component integration . service level integration

* how do you solve each of the variation point types in technology* some variation will disappear by simply analysing it with the business team and they realise that its unnecessary - harmonisation* separate bounded contexts for the legislation domain and user facts domains

most facts become value objects that can be handled with collections

domain model structure is less dependent of variation

soft-schema document based persistence * sprint contexts for java component integration* SOAP service integration handled with WS-Addressing because of the cloud infrastructure


. selling the business case

. getting product owner(s) / domain experts to think

across products

. project organisation structure for common

components and product development

. how do you defne user stories and other

requirements?

. how much upfront design?

. SPL for enterprisey software rather than

embedded systems

Jones, Lawrence G ., and L inda M . Northrop. 2010. “Clearing the Way for Software Product Line Success.” IEEE Software 27 (3) (June).

* many known pitfalls which are good to keep in mind* we've had to deal with the following already


summary

. is variation inherent to the business domain?

. are there enough products to justify payof with a

product line approach?

. analyse the variation

. design the architecture wrt commonalities and

variations

. develop a variation guide for combining common

assets and product-specifc variants

. don't forget the non-architecture challenges

* When is it relevant?* How do you go about it?


more info

http://www.se i.cmu.edu/productlines/too ls/framework/

● slides and images liberally stolen reused from

http://www.sei.cmu.edu/library/assets/spl-essentia ls.pdf

http://splc.net

* the framework has all the basic info you need to get started* Product line conference exist and the website has a nice set of case studies (HoF)

software product lines

Technology