Beginners Guide to Model-Based Systems Engineering

12/18/2018

Capturing Geospatial Library Use Cases

uc Operate GeospatialLibrary

GeospatialLibrary System

Retrieve Existing Product

<> in inventory

Deliver Image

<> GeospatialLibrary System

extension points

Assess Performance

in inventory not in inventory

Customers

<> not in inventory

Collect and Deliver New Product

<> Collectors

83

Bridging from Use Cases to Behavior: The Role of Threads

• Define distinct classes of threads based on use cases, system I/O, and/or conditions • Start with one thread per use case, class of system input, and/or conditions • Preserve each thread (for thread testing, concept of operations, etc.)

1a. Derive threads

t.1.3

t.1.4

t.1.5

t.1.6

t1.Accept& FormatRequest

t1.CheckProduct Inventory

t1.Get Product FromInventory

t1.Provide Product ToUser

1b. Partition threads

t.2.1

t.2.2

t.2.3

t.2.4

external

t2.Make Information Request

t2.Process and ProvideCollected Data

t2.Accept Products

t2.CollectData

AND

AND

t.2.5

t.2.6

t.2.7

t.2.8

t.2.9

t.2.10

2. Integrate threads to define integrated system behavior

system

t2.Accept& FormatRequest

t2.CheckProduct Inventory

t2.Prioritize Request

t2.Determine CollectorMix

t2.Provide Product ToUser

t2.TaskCollectors

10

Provide Product ToUser

In Inventory

1

2

9

AcceptAnd FormatRequest

CheckProduct Inventory

OR

Get Product FromInventory

AND

AND

5

12

NotifyUserOf Estimated Schedule

Deficiencies

Report DeficienciesAnd Recommendations

3

4

7

8

11

Not in Inventory

AcceptAnd FormatCollector Products

Evaluate Products vs. Request

Determine CollectorMix

AND

AND

Put Product In Inventory

OR

PrioritizeRequest

6

OK

TaskCollectors

84

42