ddd-crew / core-domain-charts Goto Github PK

On the README there is a missing image, namely resources/architecture-migration-core-domain-chart.jpg.

Cheers!

Hey @NTCoding !

I read your article "Legacy Architecture Modernisation With Strategic Domain-Driven Design". While reading the chapter "IT Portfolio Strategy" some question arised, I already had during my first usage of the core domain chart.

In the legend, the red dots are named as subdomains. While using the core domain chart for our IT portfolio strategy we add all our IT systems. Wouldn't it be more explicit if we name the red dot in the legend with "IT System" instead of subdomain?

If I think about the systems in my current working environemt there are systems that provides solutions for multiple subdomains. For example there is a mobile app developed by a product-aligned cross functional team. This app implements B2C features along multiple subdomains.

I am struggling a bit, what we want to visualize with a core domain chart. Is it the strategic position of a single subdomain or is it the strategic position of a IT systems? Or is it both?

Best,
Christian

Hi,

There is the definition that "Core Domains are the parts of your domain where the expected ROI is greatest, and deserve the highest focus". What I have been wondering how we should deal with domains that are not core domains but where a failure of those parts can have a huge impact on the overall organization.
Let me give a broader context here. My starting point for the question is actually a slide from @mploed (I am not trying to blame @mploed or his slides - he encouraged me to write this down somewhere here)implying that the core domain should get the best staffing that you have to deliver the. best quality; "In-House development, Excellent teams with excellent working conditions" and as we move down to supporting and generic subdomains "Don’t put your best employees into generic subdomains".
If I now look at a diagram like

I wonder whether a third axis would make sense that measures how important the domain is to deliver the overall functionality of your business / what impact a failure would have in order to assess how much attention one has to pay to that particular domain.

Lars

Hey ddd-crew,

I am preparing some modeling sessions based on the strategic DDD template. A bit unclear for me right now is the definition of a "big-bet-subdomain" and a "platform-subdomain".

Could you help me to better understand those two types? How do they differentiate from a "regular" core domain (the one in red 🙂 )

Thank you!
Christian

PS: sorry if an issue is not the correct way to ask those question. I was a bit unsure in this case.

Hi,

first of all thank you for the great resources provided here. I'm learning Wardley Maps at the moment and since the core domain charts are inspired by it I was wondering where to put the work of pioneers?

I made an extended version of a core domain chart to visualize my current understanding:

I've put the experimental area next to the core because we don't know yet if an idea will turn into a core domain. What do you think? Does it make sense?

I made a drawio version of the core domain chart. Interested? If yes, I'd love to share it 😃

At first glance, the two don't seem mutually exclusive

I made a drawio version of the core domain chart. Interested? If yes, I'd love to share it 😃

I used Core Domain Charts in some discussions with executives lately. (https://twitter.com/prooph_software/status/1291738210259939329)

Since I really like the Wardley Mapping approach of using user needs as an anchor on the map, I tried the same on a Core Domain Chart. I mapped user needs to future positions of sub domains to underline why this would be a good move. I validated the usefulness by using the charts to drive some discussions and I think it makes another good example for this repo here.

Unfortunately, I cannot use the charts and domain for a public example. I try to come up with a good example in the next weeks and create a PR. But if someone has a good one at hand, I'm happy to base my PR on top of it!

But here are screenshots from an anonymized version of such a chart. The chart focuses on one specific sub domain which Team 1 is responsible for. Above the chart you can see a part of a goal map (which I explain below). The goals are mapped to user needs and the user needs are mapped to sub domains on the chart. Only sub domains with touch points to Team 1 are included on the chart and it shows the expected future position of sub domain 1 when goals are reached and user needs met.

To keep the example simple, I'd only include user needs, but remove the goals. Even thought, for our use case the goals are essential:

Some background why I tried to mix user needs into Core Domain Chart:

Our client's c-level management created a "Goal Map". They started from the vision (their purpose), discussed most important user needs they want to address and created a map of cascading goals from long-term -> over mid-term -> to short-term goals along with KPIs for each goal. I really like the approach as a starting point to think about strategic moves that could be taken.
The idea is to communicate a rough plan to the teams. But they know that the goals alone don't make a good strategy. The teams are asked to incorporate landscape, climate and own ideas into the plan. This is planned as an iterative process. The Goal Map is not seen as a static artifact but something that is constantly refined.
The challenge is now how we can enable the teams to do that. Most of them started learning DDD a few months ago (when we joined the company to help implementing a holistic Event-first Domain Driven Design approach). I think the Core Domain Charts will help us teaching strategic thinking, so I tried to mix goals and user needs with it.

Hey everyone,

I want to take the opportunity to share my experience on how I used the core-domain-charts in my recent session.

First some explanation about the context:
We did a collaborative session with devs and domain experts for a domain that is about to be created in a company. Currently it is not completely clear for everyone, whether this domain is core, supporting or generic. And I personally assumed that based on the current distribution of information, we might not have a common understanding about either the strategic classification and domain type categorization.

The first step we made in this workshop is doing some kind of a time-boxed dot-voting. Means everyone hast to pick the red circle from the notation legend and place the domain based on his current understanding in the chart. To all of the participants who are not familiar with the difference of core, supporting and generic domains, I gave a rough overview about some characteristics. Nevertheless the two axis (business differentiation and model complexity) helped a lot.

After everyone finished, we discussed and presented the main driver for each decision. The first participant started and named the next one and so one. This raised some interesting discussions and helped to clarify the overall understanding.

In the next step, I presented the decision tree from Vladik (https://vladikk.com/2018/01/26/revisiting-the-basics-of-ddd/) and asked the participants to think about, whether they would choose a different position. And this was interesting. Some participants moved their dot into different categorizations.

In the end we found a common understanding but still struggled a bit whether it is generic or supporting.

I think the value of the chart can be maximized if we can integrate both of sub-domains and Bounded Context.
when starting in most cases Bounded Context == projections of Subdomains in solution space.
But with time some patterns like Generic Bounded Context, ...

what do you think? does it sound right to you?

An additional use case that may be considered in the list is leveraging the charts to drive some strategic discussion on delivery approaches, for example between externalization and internalization, or adoption of SaaS.