eng: Add Software Requirements Engineering chapter

Update #3715.

eng/index.rst

@@ -27,6 +27,7 @@ RTEMS Software Engineering (|version|)
     mission
     stakeholders
     prequalification
+    req-eng
     management
     test-plan
     test-framework

images/eng/req-add.puml

@@ -0,0 +1,40 @@
+' SPDX-License-Identifier: CC-BY-SA-4.0
+
+' Copyright (C) 2019 embedded brains GmbH
+
+@startuml
+
+start
+
+:Invoke: ""doorstop add RTEMS"";
+
+note right
+  This will create a new requirement.
+  For this activity its UID shall be NEW.
+  It is located in a file NEW.yml.
+end note
+
+while (Needs a link to a parent requirement?) is (Yes)
+  :Invoke: ""doorstop link NEW PARENT"";
+endwhile (No)
+
+repeat
+  :Invoke: ""doorstop edit NEW"";
+
+  :Edit the requirement according to your needs and save it;
+
+  :Commit NEW.yml with a proper message;
+
+  :Send the patch to the devel@rtems.org mailing list for review;
+repeat while (Reviewers demand changes in the new requirement?) is (Yes)
+->No;
+
+if (New requirement was accepted by reviewers?) then (Yes)
+  :Push the commit to the project repository;
+else (No)
+  :Discard the NEW requirement;
+endif
+
+stop
+
+@enduml

images/eng/req-modify.puml

@@ -0,0 +1,34 @@
+' SPDX-License-Identifier: CC-BY-SA-4.0
+
+' Copyright (C) 2019 embedded brains GmbH
+
+@startuml
+
+start
+
+repeat
+  :Invoke: ""doorstop edit REQ"";
+
+  note right
+    For this activity the UID
+    of the requirement shall be REQ.
+    It is located in a file REQ.yml.
+  end note
+
+  :Edit the requirement according to your needs and save it;
+
+  :Commit REQ.yml with a proper message;
+
+  :Send the patch to the devel@rtems.org mailing list for review;
+repeat while (Reviewers demand changes in the modified requirement?) is (Yes)
+->No;
+
+if (Modified requirement was accepted by reviewers?) then (Yes)
+  :Push the commit to the project repository;
+else (No)
+  :Keep the requirement as is;
+endif
+
+stop
+
+@enduml

images/eng/req-spec-items.puml

@@ -0,0 +1,60 @@
+' SPDX-License-Identifier: CC-BY-SA-4.0
+
+' Copyright (C) 2019 embedded brains GmbH
+
+@startuml
+
+class SpecificationItem {
+  active
+  derived
+  enabled-by
+  header
+  level
+  links
+  normative
+  rationale
+  ref
+  reviewed
+  text
+  type
+}
+
+class Interface {
+  interface-category
+  interface-type
+}
+
+class TestProcedure {
+  platform
+  steps
+}
+
+class TestCase {
+  inputs
+  outputs
+}
+
+class TestCase
+
+note right: test cases not validating\na requirement are unit tests
+
+SpecificationItem <|-- Requirement
+Requirement <|-- Functional
+Requirement <|-- NonFunctional
+NonFunctional <|-- Interface
+SpecificationItem <|-- TestProcedure
+SpecificationItem <|-- TestSuite
+SpecificationItem <|-- TestCase
+SpecificationItem <|-- Validation\nByAnalysis
+SpecificationItem <|-- Validation\nByInspection
+SpecificationItem <|-- Validation\nByReviewOfDesign
+SpecificationItem <|-- ValidationPlatform
+TestProcedure "1..n" -- TestSuite : "run by"
+TestSuite "1..n" -- TestCase : "contained in"
+ValidationPlatform "1..n" -- TestProcedure : "requires"
+Requirement "0..1" -- TestCase : "validates"
+Requirement "1" -- Validation\nByAnalysis : "validates"
+Requirement "1" -- Validation\nByInspection : "validates"
+Requirement "1" -- Validation\nByReviewOfDesign : "validates"
+
+@enduml