Learning Topic
1.Functional decomposition model
2.Context diagram
3.Use-case diagram
4.An Ecosystem Map
5. Feature Tree
6.Process flow/Swimlane diagram
1.Functional Decomposition depicts a subject and the
breakdown of that subject into smaller buckets. This
breakdown can be in multiple levels; meaning break down
the subject into the highest level components, then break
down those components into small components. This can
be done to three or four levels. Functional Decomposition
can be done on a feature basis or work basis. Using the
feature basis, you would take a system and break it down
to its highest level functions, as shown below. Using the
work basis, you would take a work initiative and break it
down to its highest level pieces of work; then break each
of those pieces of work down to smaller chunks of work.
This is useful to create a work breakdown structure and
estimating work effort.
Fig 1:
Functional Decomposition
2.The Context Diagram:
Depicts the system that is under discovery, the focus of your
change initiative, and the external entities that interact with that
system. These external entities can be systems, databases,
websites, or business units (people). This model also identifies
the data flowing between the external entities and the system
under discovery, and depicts the direction of flow for each piece
of data. One limitation of this model is that in only depicts external
entities that directly interacts with the system under discovery
fig 2: The Context Diagram
.
3.A Use Case Diagram
Is a representation of a user’s interaction with a system that
shows the relationship between and the different use cases
(functions) in which the user is involved. A use case diagram can
identify the different types of users of a system and the different
functions those users perform using the system.
Fig 3. A Use Case Diagram
4.An Ecosystem Map
shows the system under discovery and the systems which send
data to or receives data from that system. The major difference
between this model and a context diagram is that the ecosystem
map will show systems that do not interact directly with the
system under discovery; that is upstream and downstream
systems. As shown below, a website order entry system sends
the customer order to the order fulfillment system, which sends
product data to inventory system and purchasing system. The
inventory system sends the inventory transactions to the
accounting system. The accounting system also receives
purchasing transactions from the purchasing system. Even
though the order fulfillment system doesn’t interact directly with
the accounting system they are both exist in the ecosystem; and
therefore, are shown on the ecosystem map. The system(s) under
discovery will be shown with a bolder outline than the other
systems in the ecosystem map.
Fig: Ecosystem Map
5.The Feature Tree
Is a fishbone diagram showing the features within the system.
Much like the functional decomposition, the feature tree breaks
higher level features into lower level features. Level 1 (L1)
features are the highest level features and branch off the
horizontal line of the diagram. Level 2 (L2) features are lower
level features which branch off the L1 features. There is no
reason to go beyond three levels of features. You can use color
coding of the features to show what is in scope, out of scope or
features in future releases. This is an excellent model to show
executives, as it is a very easy picture that allows for a very quick
understanding of the features being looked into
Fig 5: The Feature Tree
A Process Flow illustrates high-level processes and the entities
involved in those processes. A common process flow diagram is
called a swimlane diagram.
6.Swimlane Diagram
The swimlane diagram shows processes in a row, or lane, entitled
by the entity that performs those processes. Several lanes are
depicted in a swimlane diagram so that you can see the
interactions and dependencies within the process, as shown
below.
A swimlane diagram documents the steps or activities of a
process flow or workflow. More specifically, a swimlane diagram
groups these activities into swimlanes which are horizontal or
vertical columns that contain all of the activities which fit into the
category represented by that swimlane.
The term swimlane was adopted due to the visual similarity
between the horizontal rows of the diagram to that of the
swimlanes found within a swiming pool.
Fig 6 : Swimlane Diagram