Enterprise Patterns: EASE #entarch

This pattern “Enterprise Architecture SErvices (EASE)” is a continuation of the enterprise pattern ADAGIO ( http://improving-bpm-systems.blogspot.ch/2015/12/enterprise-patterns-adagio-entarch.html ).

Architecture Delivery services

  1. Solution analysis and design service
    Contribute strongly to solution analysis, selection, integration and evolution
  2. Solution and Platforms life cycle assurance service
    Give confidence and guaranty on implemented platforms and solutions

Architecture Governance services

  1. Architecture vision, strategy and roadmap service
    Anticipate a 2-3 years enterprise systems and solutions evolution.
  2. Architecture policy and regulation service
    Supply rules and regulations, to ensure sustainability and global coherency 
  3. Architecture validation service
    Ensure information system compliance to rules and regulations

Innovation & Optimisation services

  1. Technology watch service
    Follow existing and new technologies important for the enterprise
  2. Technology-enable improvements service
    Propose and prototype how the enterprise can benefit from the technology progress 
  3. Internal consulting service
    Engage with anyone from the enterprise to apply the EA knowledge to improve operations

Management services

  1. Architecture repository management
    Capitalise knowledge for impact analysis and coherency management
  2. Business architecture management
    Give a common understanding of the organisation and its processes
  3. Application architecture management
    Provide the means to influence design decisions and/or to use proven solutions
  4. Data/Information/Content architecture management
    Provide models and conditions to manage collected, stored and transformed data
  5. Security layer management
    Ensure cross-coherency with others layers
  6. Infrastructure layer management
    Ensure cross-coherency with others layer



Beauty of #blockchain - doveryai, no proveryai (trust but verify) for voting at the digital age

The aim of this document is to provide a big picture of voting with the use of various modern technologies, primarily #blockchain. This technology is ideal to implement the “doveryai, no proveryai” (trust but verify) principle to achieve the trust.

1 Basic concepts

Each vote sheet has its unique ID which has its address in the Voting BlockChain (VBC) as VBC-ref1, which also encoded as QR-code-1.

2 Remote voting through the Internet

A Registered Voter (RV) receives a Voting Sheet (VS) via a secured channel or in a secured envelope.

The RV using a Server-Less App (SLA) in his/her internet browser.

  • Opens the VS
  • Fills it
  • Hits the button “FILLED”
  • Uploads the VS and some metadata into the VBC at VBC-ref1
  • Asks the VC to verify the voting results at VBC-ref1
  • Scans QR-code1 (e.g. mobile) to see the voting results at VBC-ref1 (optional)
  • Hits “OK” (and may save VBC-ref1)
  • Starts a smart-contract to release VBC-ref1 to the voting authorities AFTER the ballot period is over
  • Closes the SLA


3 Physical presence voting

Still a secret.



Some #entarch concepts derived from the #systemsapproach

In this blogpost I use the systems approach to derive some definitions for Enterprise Architecture (EA) subject field. The basics are in slides 3-12 of http://improving-bpm-systems.blogspot.ch/2016/07/enterprise-architecture-entarch-as.html .

System is a set of interacting discrete parts organised as a whole which exhibits (as the result of interaction between the parts) some emergent characteristics indispensable to achieve one or more stated purposes.

Any system-of-interest has an architecture which is a totality of fundamental concepts or properties of a system in its environment embodied in its discrete parts and relationships, and in the principles of its design and evolution. Architecture of a system-of-interest maybe accidental or intended depending on the way of constructing this system. In any case, any serious change in an enterprise-of-interest implies changing in its EA.

Enterprise is an emotive or motivational structure, bounded by a shared vision, shared values and mutual commitments for joint efforts to achieve one or more stated purposes. An enterprise is realized by an organisation which is a legal structure, bounded by rules, roles and responsibilities. Obviously, any modern enterprise together with its organisation is a socio-technical system (in which the interaction between people and technology is a dominant consideration). Also, an enterprise is a self-evolution system.

Thus Enterprise Architecture (EA) is architecture of an enterprise as a socio-technical system. (Although, it is correct, it is a useless definition for many people). The main and unique power of EA is the ability to objectively estimate effect (cost, benefits and risks) of potential internal changes. For example, what could be the effect of changes in a business unit which necessitates some modifications in some enterprise and departmental applications?

A good EA is the primary enabler for any internal transformations of different extent: project, program and strategy. For any transformation, EA is used to define and validate the future version of EA (called target architecture or blueprint). For example, a good EA can evaluate a level of implementability of a proposed strategy.

Usually, EA is described via a set of architecture viewpoints. Those architecture viewpoints define a set of model kinds which establish relationships between various artefacts: vision, mission, objectives, rules, servers, etc. Architecture viewpoints applied to a system-of-interest generates views whcih comprise some models.

Ideally those viewpoints are aligned, but in the reality it is not the case because different viewpoints are created by different people.

Because of the socio-technological nature of enterprises and their high-level of complexity, EA historically considered as two domain architectures:
  1. Business architecture is architecture of an enterprise considered as a social system for delivering Value (as products and/or services). Main artefacts in business-centric viewpoints are: mission, vision, products, services, directives, objectives, processes, roles, etc.
  2. IT-architecture is architecture of an enterprise considered as an IT-system. Main artefacts in IT-centric viewpoints are: IT tools, processes, and methodologies and associated equipment employed to collect, transform, transport and present information. 

The dependency between those architectures is, in theory, very straightforward. The business architecture defines the IT-architecture. But, in practice, very often, the IT-architecture evolves much slower than the business architecture, thus there is always a gap or misalignment between them.

To avoid this gap, it is necessary:
  1. version all the artefacts during their lifecycle;
  2. evlove artefacts to become digital, externalised, virtual and components of clouds;
  3. model explicitly all relationships between artefacts;
  4. make all models machine-executable, and 
  5. be able to convert models from one view to models in another view.



Beauty of #microservices: part 9 explicit coordination as a microservice

1 Introduction

This blogpost is inspired by several blogposts about microservices and it is based on the blogpost [REF1] “Architecting #cloud-friendly application architecture #apparch (inspired by #microservices)” http://improving-bpm-systems.blogspot.ch/2015/04/architecting-cloud-friendly-application.html

See also the previous blogposts of “Beauty of #microservices” series

2 Things work better when they work together, on purpose (from www.tetradian.com )

To be efficient, their work must be explicitly coordinated. Certainly, this is strongly applied to all the microservices comprise an application. Of course, it is considered that an application is a several very loosely-coupled clusters of microservices to be coordinated (for example, each such a cluster is responsible for the lifecycle of a particular business entity).

Although there is an opinion that “Service is not comprised of other services due to the independence requirement” (see https://www2.opengroup.org/ogsys/catalog/W169), it is considered that some (with bigger responsibility) microservices can be assembled from other (with smaller responsivity) microservices.

There are several techniques to implement coordination.


  • nature: centralised at design-time and centralised at run-time thus may be explicit
  • specific: there is a misconception that it uses only synchronous communication (à la RPC) although it may use also asynchronous communication (à la message-passing)


  • nature: decentralised at design-time and decentralised at run-time thus implicit
  • specific: uses only asynchronous communication (à la message-passing)

Reactive streams and runnable graphs

  • nature: decentralised at design-time and centralised at run-time thus implicit
  • specific: optimised for high volume event processing


  • nature: centralised at design time and decentralised at run-time thus explicit
  • specific: each case is a completely separate instance with its own lifecycle; and the process may be another microservice

3 Implementation of business-process-based coordination

Of course, it should be a DSL to define an explicit coordination (e.g. BPEL, BPMN, etc.). Using the terminology from the section 7 of [REF1], a DSL-processor may act as a specialised container for DSL-scripts. Also, some microservices which are coordinated by a DSL-script may use some specialised containers. For example, a specialised container for human-operations, a specialised container for business rules, a few specialised containers for automated-operations.

4 Conclusion

Some advantages of the business-process-based technique:
  • Assembled microservices have no routing logic (thus they follow SRP). 
  • All the necessary microservices (assembled and dependent) can be instance-bound (help to predictive analytics).
  • All the necessary microservices (assembled and dependent) can be instantiated on demand (this minimises DEVOPS).
  • A particular instance may be stopped for the error-recovery without influencing other instances (operational isolation).
  • A few versions of the same coordination (i.e. business process) may co-exist (versioning is easy).
  • Different instances of the same process and their may be executed on different nodes (linear scaling out).
  • Easy to visualise for the business people.



Beauty of #microservices: part 8 dumb-pipes & smart-containers & minimalistic-microservices

1 Introduction

This blogpost is inspired by several blogposts about microservices and it is based on the blogpost [REF1] “Architecting #cloud-friendly application architecture #apparch (inspired by #microservices)” http://improving-bpm-systems.blogspot.ch/2015/04/architecting-cloud-friendly-application.html

See also the previous blogposts of “Beauty of #microservices” series

2 Importance of containers for microservices

This blogpost is inspired by two comments to my blogpost about microservices:
  • Igor Topalov “microservices shall be considered in conjunction with containers” 
  • Bogdan Năforniţă “considering transactions moves us away from the concept of ‘smart endpoints, dumb pipes’” 
Considering the SRP is one of commonly-agreed characteristics of microservices, the “Smart endpoints and dumb pipes” characteristic is in the direct contradiction to the SRP. Making endpoints (i.e. microservices) “smart” requires that they have to have many various functionality in addition to their “core” functionality. Thus the question is how to allow simplify microservices and thus simplify the life of software developers.

I used several types of nested primitive containers:

generic – JVM on top of any popular OS (experience in programming of portable software helped);

language-specific – Jython on top of JVM to run small Python programs, and

specialised – particular environment on top of Jython on top of JVM; this environment considerably simplified the development of automation and integration functionality.

With each nested container, my microservices became more functional and easier to evolve. Finally, each of them was as small text fragments stored in a source version control tool; they were loaded into containers dynamically (at the run-time) and they could dynamically load some modules. Devops was minimal.

3 Conclusion

  • Keep pipes dumb (no logic!).
  • Create your own smart containers (maximum housekeeping and specialisation) from some standard ones.
  • Help your microservices be functionally minimalistic (thus simplify the life of your software developers).



Beauty of #microservices: part 7 breaking the monolith

1 Introduction

This blogpost is inspired by several blogposts about microservices and it is based on the blogpost [REF1] “Architecting #cloud-friendly application architecture #apparch (inspired by #microservices)” http://improving-bpm-systems.blogspot.ch/2015/04/architecting-cloud-friendly-application.html

See also the previous blogposts of “Beauty of #microservices” series

2 Breaking the monolith

This blogpost is a continuation of two previous ones:
Below, a series of steps to show how to remove from a monolith (actually a home-made ERP) some functionality around a particular Business Entity (BE) or a group of BEs.

At the AS-IS step, the monolith is the master of everything related to this BE (thisBE) – data, rules, processes and events (which are generated during the lifecycle of this BE and may affect other BEs.)

The first step is to externalise and make explicit the process to manage this BE in a BPM-suite tool. Keeping of thisBE (i.e. its data) is externalised as well. Also the associated rules must be externalised (as a copy) to reproduce the business logic spread in the monolith.

The monolith keeps its slave copy of data which are maintained via some stor-API. The associated business logic and event logic are still managed by the monolith. The data (as a slave) must always stay in the monolith because they may be used somewhere.

The second step is to externalise rules (when they are good enough to cover all the existing rules from the monolith).

At the TO-BE step, everything related to thisBE is externalised, but the associated events must be “injected” into the monolith by some func-API.

3 Anti-pattern DOUM

Avoid the "DOUble Master" (DOUM) anti-pattern (section 5.6 of my book "Improving enterprise BPM systems" http://www.improving-bpm-systems.com/book ).

As coordination can be carried out by an application or by a process engine, we have to be very careful to avoid the “double master” anti-pattern. At any moment in time there must be only one master responsible for the coordination of a particular process instance. (Of course, the coordination role may be delegated if appropriate.) This is analogous to a well-organised meeting where the chairperson decides who talks next.

The non-recognition of this anti-pattern can be very costly. We have observed a BPM solution which allowed the modification of data by a process engine, by an interactive application (i.e. by a human) and by a batch at the same time. The coordination of activities was based on data and, if necessary, the application or the batch could “correct” the process. The process engine was used mainly for the handling of three human activities, and the implementation of this solution (for a relatively simple business process) took several man-years.

4 Conclusion

How will you eat an elephant? Piece-by-piece, of course.


Beauty of #microservices: part 6 managing state is a teamwork

1 Introduction

This blogpost is inspired by several blogposts about microservices and it is based on the blogpost [REF1] “Architecting #cloud-friendly application architecture #apparch (inspired by #microservices)” http://improving-bpm-systems.blogspot.ch/2015/04/architecting-cloud-friendly-application.html

See also the previous blogposts of “Beauty of #microservices” series.

2 Managing state is a teamwork

Obviously, a solution or an application implemented with microservices is a set or suite of stateful and stateless microservices. The chapter 7 of REF1 provides a classification of microservices. The stateful microservices are those which:
  1. manage some resources
  2. provide legacy functionality 
  3. assemble (implicitly and explicitly) other microservices
Each stateful microservice must be, ideally, idempotent to contribute to managing state.

Microservices, which manage some resources, may have a few impotency pitfalls to be avoided. For example, the read operation may be not idempotent if concurrent updates are possible. The update (or write) operation may be not idempotent if it can change some metadata, e.g. modification date. Also, idempotency may depend on a particular operation. The safest way is to create a small “shell” to guarantee the idempotency and a unique ID for each invocation.

Also, a small “shell” is only the option for microservices, which provide legacy functionality (they are considered as black boxes).

Microservices, which implicitly assemble other microservices, are a real pain because they have to be carefully reviewed about their idempotency. A possible approach for their idempotency is to re-execute again such a microservice. If all the microservices, which are invoked from it, are idempotent and don’t have any human involvement then such a re-execution will be idempotent as well.

Microservices, which explicitly assemble other microservices, may create some “check-points” (similar to mainframe batch systems) to start their re-execution from the last “passed” checkpoint. Of course, the data associated with checkpoints must be stored somewhere else as records. ( A similar approach can be found in http://www.theidentitycookbook.com/2016/06/blockchain-for-identity-access-request.html )

3 Error recovery (and distributed transactions)

As microservices form a distributed system, the error recovery is very difficult.

Explicit assembly of microservice, e.g. a business process in BPMN, can implement the error recovery in the following way.

Imagine a process fragment with three automated activities (A, B, and C) to be executed as a transaction. Each of those activities is an invocation of a microservice and the normal execution sequence is E2-A-B-C-E4.  Because any of those microservices may fail, this fragment contains the intermediate event E3 to intercept a failure and an activity for Error Recovery Procedure (ERP); the latter may be a human activity.

The first pass (with a failure of activity B ) has the following sequence:


The second pass (with a failure of activity C) has the following trace:

E2-A(already done)-B(done)-C(failed)-E3-ERP

The third pass (with no failures) has the following trace:

E2-A(already done)-B(already done)-C(done)-E4

Activity A was executed 3 times, but it did the real work only at the first time – two other times were ignored because it is idempotent.

An extension with a timeout can be found in http://improving-bpm-systems.blogspot.ch/2014/08/bpm-for-digital-age-shifting.html

This way can be used also for implementing distributed transactions (please, note, some compensation activities may be necessary).

A similar approach was described at http://www.grahamlea.com/2016/08/distributed-transactions-microservices-icebergs/

4 Conclusion

Microservice architecture requires common efforts from microservices to achieve
  • state management, 
  • error recovery and 
  • distributed transactions.