Archive for June, 2015

Which UML diagram types are in most demand?

  1. From a recent spot check of over 500 job postings on that mention both “UML” and “diagram”, the following picture emerges:
  2. There is clearly a Big 4 of UML diagram types, and they are  – in order of frequency –
    1. sequence,
    2. use-case,
    3. activity and
    4. (the only structural diagram type that “counts”) class diagram.
  3. UML Diagram Type Count of type
    activity 19.33%
    class 15.33%
    communication 6.00%
    component 2.67%
    interaction 1.33%
    network-architecture 1.33%
    object 2.00%
    sequence 23.33%
    state 8.00%
    timing 0.67%
    use-case 20.00%
    Grand Total 100.00%
  4. It seems you could in practice cover “80%’ of UML with these four diagram types. Even state and communication  (collaboration) diagrams are an already very distant 5th and 6th (but get you up to a coverage of about 95%).
  5. Notably, the majority of UML diagram types – at least in this sample set – do not figure at all:
Count of type Diagram
0 Behavioral state machine
0 Collaboration use
0 Composite structure
0 Deployment
0 Information flow
0 Interaction overview
0 Internal structure
0 Manifestation
0 Model
0 Package
0 Profile
0 Protocol state machine

Note: The vast majority of mentions did not need any, but I attempted some translations of the raw data on counted as
action activity
collaboration (1) communication (2)
data flow information flow
domain model class diagram
object models object
state charts state machine
process flow 1 not counted
swim lane sequence
prototypes 1 not counted
Categories: service-is-documenting Tags: