I was promoted recently as a software architect in a Software development company that produces an Enterprise Content Management product for a customer segment that includes the likes of Insurance companies, Healthcare companies, Research companies and Government agencies.
I had designed moderately complex applications at this organization and my previous jobs.
As a new architect I want to explore Domain Driven Design concepts and various architecture types for migration of our product to a cloud service provider and metamorphize our product from a media based deployment to Software as Service (SAAS) offering.
In my opinion to do this correctly, I will need to create a domain model from the domain for which the software is written.
However the problem I am having is determining what the domain for a product software company is when their products caters to varying needs of disparate customer verticals. I suspect the domain is some kind of meta-domain and not a regular business domain like shipping, insurance or healthcare.
I have following question for this scenario
Question: In terms of Domain Driven Development, what would be the domain of such a company and how can I articulate it so, I can create a domain model?
Identifying the Core Domain can be tricky because the core purpose of your software application can be obfuscated because of all the supporting features that need to be present to make the application useful.
These clues may help you identify and categorize functionality between your Core Domain and Supporting Domains:
Is your software no longer identifiable from a product outside your domain category if you remove a piece of the functionality? You are dealing with a Core Domain.
What is your company's Vision/Mission/Differentiator Statement? They usually reveal the Core Domain.
What category are you and your competitors grouped into in industry reports like Gartner provided? That is your Core Domain.
If your product addresses different customer domains, what common features are used by almost all of them? That is your Core Domain.
Is functionality an industry standard? Does everybody else have it too? Instead of building it, can you buy software off-the-shelf and integrate it into your application, if one were available? If yes, you are dealing with a Supporting Domain.
If you were to remove some functionality because customers do not use it or don't value it enough, would your product still be marketable? That is a Supporting Domain.
Answering these questions will point you in the right direction, but the boundaries of your core domain can be unique to your product's value proposition. Don't hesitate to expand and contract the core domain as the product grows and matures.
Most importantly, talk to your Domain Experts and Salespeople. They usually have a very good idea of what the product pitch is, what is the core value, and what are addons.
Related
The problem I'm facing is the design of an integration platform.
The company has different tools used for selling online financial services and wants to unify the selling process by creating a common integration platform.
Existing tools range from simply designing a tailor-made offer, to managing all the phases of listing to selling and supporting. The integration platform should orchestrate all the tools.
So I do approach this problem from a DDD point of view?
Domain: selling online services
subdomains: service catalog, request offers, sending offers, buying service, support customer.
bounded context? maybe integration with other company systems like identities and invoices?
My trouble with this is that some existing applications encompass several subdomains, others don't. Also, some applications working in the same subdomain have completely different languages, for example, service vs product, vs project...
How does an integration platform fit in this picture and how would you approach it from a DDD point of view? (or maybe it's a completely wrong approach and should I leave DDD inside each tool and treat them as bounded context?)
I recommend extracting the common bits of meaning (ignoring their names) from the various applications into common domains/bounded contexts. Each bounded context has anti-corruption layers that essentially adapt the language used in one or more existing applications to the one used in the common domain (and vice versa). Then you can cut over the existing applications piece-by-piece to use the respective ACLs to take advantage of the common domain implementation.
Eventually, you might even be able to dispense with the ACLs, as the language becomes more ubiquitous, but it's also perfectly okay to keep them around forever: the ACLs introduce some indirection (and possibly complexity, e.g. if they're deployed as their own microservices) but that's the price you pay for limiting coupling to the ACL.
(It's not clear from the question how experienced you are with DDD).
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 5 years ago.
Improve this question
I am a web developer, I want to become software architect, and I learn everyday about it, but when I am learning software architecture I see TOGAF framework for enterprise architecture, I want to get solid understand in an enterprise architecture.
Overview
Enterprise architecture focuses on the future state solution for : Current business problem , business strategy , business process improvement (BPI), business process re-engineering and business adventures. If you ask one enterprise architect what they are working on, most likely you are going to find out that they are working on one of these areas, unless they have a more specialized domain, which we cover later in this article.
“The What”
Enterprise Architecture does not prescribe the “how” only the what,
Deliverables
Depending on your company solution lifecycle standards and templates, your deliverable may be called “solution architecture”, “Enterprise Architecture blueprint” or some other name.
Architecture layers
It is a good practice to include in your deliverable minimum six architecture layers:
Security: End to end view of your solution from security perspective, this captures authentication and access management, data in transit and at rest protection.
Application: A view of your solution from the application perspective, includes domain specific programming language, and application design patterns and decisions for your font end, back-end and middle tier.
Infrastructure: This layer shows a view of your running platform, it may include cloud, containerization and virtualization.
Information: This captures your entire information lifecycle management from data modeling to acquisition, classification, and retirement.
Network: This architecture layer depicts the network end points and their paths.
Integration: This layer shows your data transportation and systems conversations, for example it shows your separations of data transportation from orchestration.
While these layers are not the only layers hat you can add to your architecture, you can add more as needed for example “business continuity” and “devops”, but all depends on the type of your organization and objectives.
The Enterprise Architect role
Being an Enterprise Architect (EA) entails command in multiple domains , however most of us in this industry started our careers in one domain such as development, networking, DBA, etc, an architect usually have expertise in at least one of the following and experience in the rest.
Expertise in one programming language (expert level means very familiar with the language and design patterns specific to the language).
Expertise in one database vendor ( Oracle, MSSql, DB2) expert level means - - Expertise in SQL , SQL:2016 being the latest standard in addition to server side language (PLSQL, TSQL)
Experience in networking basic concepts of networking and knowledge of new trends such as software defined networks (SDN).
Experience in integration patterns
Experience in infrastructure such as cloud , virtualization and containerization
Experience in information security: Identity and access management , Data in transit and data at rest protection.
In addition basic knowledge in : Data modeling, data warehousing, big data, Web UI frameworks, major cloud providers, compliance (ie: PCI, HIPPA), IPV4, IPV6, SOA.
And also helps if you have your own vision of the future landscape (ie: server-less , self-rendering services )
Architecture frameworks
There are multiple frameworks that depending on the situation may fit in your deliverables, these frameworks try to address the common architecture patterns in a prescriptive way.
TOGAF
Zachman
DoDAF
To answer your question " what s the difference between system architecture, application, software architecture":
Application architecture is one of the layers in your architecture.
System architecture, software architecture, solution architecture can be used interchangeably. Just don't lose your the big picture .
Some of the inputs for the architecture are
business strategy.
use cases
business cases.
Business continuity strategy
Compliance
Some of the outputs are
High level designs
A vertical partition) of your architecture layers.
Software specifications
A prescriptive and technology oriented specifications of your solution.
I have presented on Enterprise Architecture a few times over the past couple of years. One of the quotes (from myself) that I use in my talks is: "Just because I am an Enterprise Architect, that does not mean that I am an Enterprise Architect". That might seem like a strange quote but it's basically just a fun way to say that enterprise architecture can mean different things to different organizations and people.
Enterprise architects tend to work across a broad domain of concerns, occasionally focusing on specific aspects of a specific technology and/or business process. Some organizations (they tend to be the ones with a more mature EA practice) will have architects that work across all domains within the organization (or, enterprise - hence enterprise architect). Some organizations will have specific types of architects (e.g. applications architect, solutions architect, data architect, network/systems architect, business architect, etc.) that focus on a particular area. Having various types of architects within an organization is one way to "ease" yourself into the architecture space.
For example, the organization I work for has the role, Lead Developer. Each development team has a lead developer and they essentially act as applications architects (even if that is not their specific title). For someone new to that role, they focus on learning the business domain their team is typically responsible for. They also provide the overall architectural vision and design for the apps their team produces. And, they also work closely with the enterprise architects to ensure they are working within the parameters of the organization as a whole (i.e. not reinventing the wheel or making use of a technology or approach that does not fit within the enterprise architecture as a whole).
Starting out as a lead developer is one way to get your foot in the door, so to speak. There are other ways. For example, if you're interested in data architecture, then joining a BI team would be a great way to learn more about data architecture at scale. Joining a network team would go a long way toward gaining knowledge that could be applied as a network/systems architect.
You mention TOGAF in your question above but there are many architectural frameworks out there (TOGAF, Zachman, DoDAF, etc.). Depending upon your specific situation, a "canned" framework might make sense for your organization and it might not. However, becoming familiar with some of the available frameworks will give you insights into some of the common challenges faced by enterprise architects. In the end, however, you will want to do what is right for your organization. You might take bits and pieces from multiple frameworks and wrap them all up into your own framework. As with many challenges, do what works for you.
Along with everything else, keep in mind that enterprise architects tend to think strategically and keep a focus on the future. That does not mean that they do not think tactically or are not concerned with the "here and now". They just tend to have strengths when it comes to strategy and vision.
While this is a bit of a wordy answer, the reality is that nothing beats experience. If you want to become an enterprise architect then you should try to apply architectural practices to your everyday tasks. The more you work and act like an enterprise architect the more ready you will be when an opportunity presents itself.
Hope this helps!
If you want to be a software architect - aka Application Architect, then TOGAF is useful to know, but not necessary for you. Enterprise architects deal with things that impact the entire organisation, particularly things like Strategy & Planning. Organisational modelling, etc.
They can be sometimes involved as a governance role to ensure alignment with organisational design standards, or security standards. They can also sometimes be involved in setting organisational policy.
Either way - too many people assuming taking the "most senior looking" title will get them the best pay and the best life - this is not always true and an EA role is very very different to a software architect - even though they are both "Architects"
Now getting a solid understanding of Enterprise Archtiecture will be a challenge - because 1. its kind of undefined right now - or more accurately - there is around 460+ different models of what an Enterprise Architecture is - TOGAF only being one of them. 2. Most EAs like to get completely OCD around model definitions, and each one has a different OCD point of view exactly what they are - I should know, I'm one of them :)
One of the best general models I have found is DoDAF, but it sure isn't light bedtime reading. Wikipedia has a reasonably light definition though and it might be worth starting there if you haven't already
Enterprise Architecture (EA) entails the whole organization and possibly beyond. It includes Business Architecture, Information Architecture, Technology Architecture & Application Architecture. EA is strategic and thus it is "What" needs to be done.
I am studying Domain Modeling/UML Class diagrams and some of the words aren't being explained in a way I can understand.
I just found out through this wonderful website what "domain" means, is application domain just as simply explained?
There is typically a problem domain and a solution domain. The problem domain describes a situation that needs improvement. For example, it can describe the concepts and processes in a human resources department. The solution domain describe one of possibly many solutions to a problem. One solution might be a streamlined process, another might be an application that takes over parts of a process. An application domain would fall under the solution domain. It would be a description of an application that improves the state of the problem domain.
So, there are three main levels you should distinct:
Project - how you work is organized
Product - the result of your work
Domain : your work helps to some business. That business and its rules and flows is the Domain.
Project is above product, product is above domain.
Some may nit pick over a perception of subtle (or major) differences between the application and solution domain. For the most part and at least in all the software engineering text books I've read the terms are often used interchangeably and will differ in their precise meaning from author to author. This can cause confusion as I've seen application used in two conflicting contexts.
Problem/ Application Domain: The domain in which the software system will be expected to run and survive. As in this is the domain in which the software system will be applied to.
Application/Solution Domain: The software solution/application applied to the problem domain to meet a client's requirements
For these reasons, I dislike the phrase Application Domain because of its potential for ambiguity in how it may be interpreted. I prefer to say 'Problem Domain' (situation in which the software will be used) and 'Solution Domain' (the software and systems built to solve issues in the problem domain).
I am having difficulty in attempting to ascertain which domain within a given model can be considered the "core domain". It can be tricky especially if there are several domains which are core to the function of a business.
I would like someone to outline a systematic process to single out the core domain when dealing with a system that has multiple candidates.
Core domain - the most important subdomain, which is essential for the business. Without it the business would fail. If you ever need to pick the first solution to implement - start with the core domain.
Supporting subdomain - subdomain, which is less valuable for business than Core domain. Without it business may be can even survive for some time. But it still is quite important (supports core domain), it also is specific for the domain and has to be developed. In this case, for some reason, we can't buy an existing software or component to solve the problem.
Generic subdomain - subdomain which is less valuable for business than Core domain. It also is generic enough to allow buying it off the shelf (unlike supporting domain).
Do you exactly mean multiple core domain candidates or may be it is multiple bounded contexts in core domain?
"Can Core Domain span multiple Bounded Contexts?" - another SO question
Eric asks several questions to help us identity which parts are core
to the domain:
What makes the system worth writing?
Why not buy it off the shelf?
Why not outsource it?
The core domain is so critical and fundamental to the business that it
gives you a competitive advantage and is a foundational concept behind
the business.
Source
Can somebody please explain (in succinct terms) what exactly is domain driven design? I see the term quite a lot but really don't understand what it is or what it looks like. How does it differ from non-domain driven design?
Also, can somebody explain what a Domain Object is? How does domain differ from normal objects?
EDIT:
As this seem to be a top result on Google and my answer below is not, please refer to this much better answer:
https://stackoverflow.com/a/1222488/1240557
OLD ANSWER (not so complete :))
In order to create good software, you have to know what that software
is all about. You cannot create a banking software system unless you
have a good understanding of what banking is all about, one must
understand the domain of banking.
From: Domain Driven Design by Eric Evans.
This book does a pretty good job of describing DDD.
Register to download a summary of the book.
Domain Driven Design is a methodology and process prescription for the development of complex systems whose focus is mapping activities, tasks, events, and data within a problem domain into the technology artifacts of a solution domain.
The emphasis of Domain Driven Design is to understand the problem domain in order to create an abstract model of the problem domain which can then be implemented in a particular set of technologies. Domain Driven Design as a methodology provides guidelines for how this model development and technology development can result in a system that meets the needs of the people using it while also being robust in the face of change in the problem domain.
The process side of Domain Driven Design involves the collaboration between domain experts, people who know the problem domain, and the design/architecture experts, people who know the solution domain. The idea is to have a shared model with shared language so that as people from these two different domains with their two different perspectives discuss the solution they are actually discussing a shared knowledge base with shared concepts.
The lack of a shared problem domain understanding between the people who need a particular system and the people who are designing and implementing the system seems to be a core impediment to successful projects. Domain Driven Design is a methodology to address this impediment.
It is more than having an object model. The focus is really about the shared communication and improving collaboration so that the actual needs within the problem domain can be discovered and an appropriate solution created to meet those needs.
Domain-Driven Design: The Good and The Challenging provides a brief overview with this comment:
DDD helps discover the top-level architecture and inform about the
mechanics and dynamics of the domain that the software needs to
replicate. Concretely, it means that a well done DDD analysis
minimizes misunderstandings between domain experts and software
architects, and it reduces the subsequent number of expensive requests
for change. By splitting the domain complexity in smaller contexts,
DDD avoids forcing project architects to design a bloated object
model, which is where a lot of time is lost in working out
implementation details — in part because the number of entities to
deal with often grows beyond the size of conference-room white boards.
Also see this article Domain Driven Design for Services Architecture which provides a short example. The article provides the following thumbnail description of Domain Driven Design.
Domain Driven Design advocates modeling based on the reality of
business as relevant to our use cases. As it is now getting older and
hype level decreasing, many of us forget that the DDD approach really
helps in understanding the problem at hand and design software towards
the common understanding of the solution. When building applications,
DDD talks about problems as domains and subdomains. It describes
independent steps/areas of problems as bounded contexts, emphasizes a
common language to talk about these problems, and adds many technical
concepts, like entities, value objects and aggregate root rules to
support the implementation.
Martin Fowler has written a number of articles in which Domain Driven Design as a methodology is mentioned. For instance this article, BoundedContext, provides an overview of the bounded context concept from Domain Driven Development.
In those younger days we were advised to build a unified model of the
entire business, but DDD recognizes that we've learned that "total
unification of the domain model for a large system will not be
feasible or cost-effective" 1. So instead DDD divides up a large
system into Bounded Contexts, each of which can have a unified model -
essentially a way of structuring MultipleCanonicalModels.
You CAN ONLY understand Domain driven design by first comprehending what the following are:
What is a domain?
The field for which a system is built. Airport management, insurance sales, coffee shops, orbital flight, you name it.
It's not unusual for an application to span several different domains. For example, an online retail system might be working in the domains of shipping (picking appropriate ways to deliver, depending on items and destination), pricing (including promotions and user-specific pricing by, say, location), and recommendations (calculating related products by purchase history).
What is a model?
"A useful approximation to the problem at hand." -- Gerry Sussman
An Employee class is not a real employee. It models a real employee. We know that the model does not capture everything about real employees, and that's not the point of it. It's only meant to capture what we are interested in for the current context.
Different domains may be interested in different ways to model the same thing. For example, the salary department and the human resources department may model employees in different ways.
What is a domain model?
A model for a domain.
What is Domain-Driven Design (DDD)?
It is a development approach that deeply values the domain model and connects it to the implementation. DDD was coined and initially developed by Eric Evans.
Culled from here
Here is another good article that you may check out on Domain Driven Design. if your application is anything serious than college assignment. The basic premise is structure everything around your entities and have a strong domain model. Differentiate between services that provide infrastructure related things (like sending email, persisting data) and services that actually do things that are your core business requirments.
Hope that helps.
As in TDD & BDD you/ team focus the most on test and behavior of the system than code implementation.
Similar way when system analyst, product owner, development team and ofcourse the code - entities/ classes, variables, functions, user interfaces processes communicate using the same language, its called Domain Driven Design
DDD is a thought process. When modeling a design of software you need to keep business domain/process in the center of attention rather than data structures, data flows, technology, internal and external dependencies.
There are many approaches to model systerm using DDD
event sourcing (using events as a single source of truth)
relational databases
graph databases
using functional languages
Domain object:
In very naive words, an object which
has name based on business process/flow
has complete control on its internal state i.e exposes methods to manipulate state.
always fulfill all business invariants/business rules in context of its use.
follows single responsibility principle
DDD(domain driven design) is a useful concept for analyse of requirements of a project and handling the complexity of these requirements.Before that people were analysing these requirements with considering the relationships between classes and tables and in fact their design were based on database tables relationships it is not old but it has some problems:
In big projects with complex requirements it is not useful although this is a great way of design for small projects.
when you are dealing with none technical persons that they don,t have technical concept, this conflict may cause some huge problems in our project.
So DDD handle the first problem with considering the main project as a Domain and splitting each part of this project to small pieces which we are famous to Bounded Context and each of them do not have any influence on other pieces.
And the second problem has been solved with a ubiquitous language which is a common language between technical team members and Product owners which are not technical but have enough knowledge about their requirements
Generally the simple definition for Domain is the main project that makes money for the owners and other teams.
I do not want to repeat others' answers, so, in short I explain some common misunderstanding
Practical resource: PATTERNS, PRINCIPLES, AND PRACTICES OF DOMAIN-DRIVEN DESIGN by Scott Millett
It is a methodology for complicated business systems. It takes all the technical matters out when communicating with business experts
It provides an extensive understanding of (simplified and distilled model of) business across the whole dev team.
it keeps business model in sync with code model by using ubiquitous language (the language understood by the whole dev team, business experts, business analysts, ...), which is used for communication within the dev team or dev with other teams
It has nothing to do with Project Management. Although it can be perfectly used in project management methods like Agile.
You should avoid using it all across your project
DDD stresses the need to focus the most effort on the core subdomain. The core subdomain is the
area of your product that will be the difference between it being a success and it being a failure. It’s
the product’s unique selling point, the reason it is being built rather than bought.
Basically, it is because it takes too much time and effort. So, it is suggested to break down the whole domain into subdomain and just apply it in those with high business value. (ex not in generic subdomain like email, ...)
It is not object oriented programming. It is mostly problem solving approach and (sometimes) you do not need to use OO patterns (such as Gang of Four) in your domain models. Simply because it can not be understood by Business Experts (they do not know much about Factory, Decorator, ...). There are even some patterns in DDD (such as The Transaction Script, Table Module) which are not 100% in line with OO concepts.
I believe the following pdf will give you the bigger picture. Domain Driven Design by Eric Evans
NOTE: Think of a project you can work on, apply the little things you understood and see best practices. It will help you to grow your ability to the micro service architecture design approach too.
Get an organization wide understanding of the problem domain by
developing a ubiquitous language (a common mental model) per sub-problem-domain.
Use that language as close as possible in solution domains (code).
Only then choose technologies.
Don't be technology driven but problem domain or business driven.