Quality Assurance for Information System UNICAM

Structural and Behaviroal Correctness

The validity and completness of the model

Understandability

Maintainablity

Learning

Comformance of a process model to the syntactic rules of the language used

is structurally and behaviorally correct

• Element-level rules:
  • E.g., Activities must have at least one incoming and one outgoing sequence flow
  • start events must not have incoming arcs, end events must not have outgoing arcs
• Model-level rules:
  • All flow nodes must be on a path from a start to an end event
    • E.g., no dangling arcs or disconnected nodes
    • Implies that a model should have at least one start and one end event

A model is sound if it satisfies the following behavioral rules:

1. Option to complete: Any running process instance must eventually complete
2. Proper Completion: at the moment of completion, each token of the process instance should be in a different end event
3. No dead activities: Any activity can be executed in at least one process instance.

adherence of a process model to its real-world process

checking the semantic quality of a model by comapring it with its real word business process

• Activities model something actively performed during the process
• Events model something happening instantaneously during the process
• AND gateways model parallelism
• XOR gateways model exclusive decisions and simple merging points
• OR gateways model inclusive decisions and synchronizing merging points

(all possible process instances are covered)

“This model captures an order fulfilment process that takes place at a seller. The model starts with the receipt of an order…”

usability of a process model

how easy it is to read and comprehend the model

how easy it is to apply changes

how good a model reveals how its corresponding process works in reality

Validate / Validation of the model

Verifcation of the model

certifiication

use as few elements in the model as possible

minimize the routing paths per element

use one start event and one end event

model as structures as possible

avoid or gateways where possible

use verb-object activity labels

decompose a model with more than 30 elements

pragrmatic

• How can we guarantee that a model is UNDERSTANDABLE?

HOW can we help the modeler to design UNDERSTANDABLE models

General

Notation

Labelling

Patterns

Appearance

1. Validate the model / Comply with BPMN Standard / Use a Validator SW
   1. True or False Metrics 1/0
2. Minimize the model size / less is better >31 / by counting
   1. 0 if =<31, 1 if more
3. Apply hierarchical structure with subprocess /split up into multi-layer sub-processes
   1. 0 if > 31 & SB < 0, 1 otherwise
4. Apply symmetric modelling
   1. Fore every node splitting there is a node to coming together (Gateways)
5. Highlight the happy path
   1. A sequence of activities that will be executed if everything goes as expected.

1. Minimize Concurrency
   1. Reduce the use of parallel gateways and ad-hoc processes.
   2. Especially if parallel gateways are executed by manually and only one person is responsible for the activity
2. Model loops via activity looping
   1. Model a loop via activity looping (loop marker) instead of using a sequence flow

1. Activity Description / a brief description for each activity in the model
   1. 0 if empty / 1 otherwise
2. Minimize gateway heterogeneity
   1. Less several type of gateway may cause lesser confusion
   2. 0 if GH < 0.92 / 1 otherwise

1. Consistent usage of pools
   1. Define as many pools as processes and or participants. Use Blackbox pool (customer) for external participants -> linked to main process pool by message lines
2. Consistent usage of lanes
   1. Internal organization units as lanes within a single process pool, not as sperate pools – otherwise implies independent processes. Only create a lane if at least 1 activity is within.
   2. Activity two lanes at the same time -> Archimate Mode
3. Explicit usage of start and end events
   1. Implicit start and end events lead to misinterpretations. Any start needs a end
4. Consistent usage of start events
   1. Include only one start event – if needed use event-based start gateway

1. Labeling Activities
   1. Activities one verb, and one object. Verb present tense and be familiar to the organization. Object has to be qualified and also of meaning to business.
   2. Not multiple activities the same name
   3. Send and receive only for such activities
2. Labeling AND-Gateways
   1. Should omit labels on AND
3. Labeling Data Object
   1. A qualified NOUN – meaningful for business
4. Multiple instances of the same data object using a matching label followed by the