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Tag Archives: UML
Software Duct Tape – Binding the C++ Universe Together
Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
Latest posts by Glennan Carnie (see all)
- Practice makes perfect, part 3 – Idiomatic kata - February 27, 2020
- Practice makes perfect, part 2– foundation kata - February 13, 2020
- Practice makes perfect, part 1 – Code kata - January 30, 2020
One of the cornerstones of object-oriented design is the concept of objects interacting by sending messages to form mechanisms – units of higher-order (or ‘emergent’) behaviour.
In order to send a message (in this case, invoke a member function) an object must have a ‘link’ to the target object. That link is formed by building in an association between the two classes as part of the type’s definition.
In this article we look at building associations between classes and forming run-time links […]
Sailing the Seven C’s of design*
Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
Latest posts by Glennan Carnie (see all)
- Practice makes perfect, part 3 – Idiomatic kata - February 27, 2020
- Practice makes perfect, part 2– foundation kata - February 13, 2020
- Practice makes perfect, part 1 – Code kata - January 30, 2020
I’m always looking for nice little mnemonics to help out remember the important concepts in design. Here’s one for model-driven development I call the “Seven C’s”. It basically enumerates the seven stages a design goes through, from initial idea to code.
CONCEPT The Concept phase is about understanding the problem. In other words: requirements analysis. When you’re in Concept mode your main focus is on validation – am I solving the right problem for my […]
Posted in Design Issues
Tagged design, MDA, MDD, methodologies, modelling, techniques, UML
2 Comments
Overcoming Name Clashes in Multiple C++ Interfaces
Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Latest posts by Niall Cooling (see all)
- Disassembling a Cortex-M raw binary file with Ghidra - December 20, 2022
- Using final in C++ to improve performance - November 14, 2022
- Understanding Arm Cortex-M Intel-Hex (ihex) files - October 12, 2022
Interfaces
One of our key design goals is to reduce coupling between objects and classes. By keeping coupling to a minimum a design is more resilient to change imposed by new feature requests or missing requirements[1].
An Interface represents an abstract service. That is, it is the specification of a set of behaviours (operations) that represent a problem that needs to be solved.
An Interface is more than a set of cohesive operations. The Interface can be thought of as a contract […]
The Baker’s Dozen of Use Cases
Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
Latest posts by Glennan Carnie (see all)
- Practice makes perfect, part 3 – Idiomatic kata - February 27, 2020
- Practice makes perfect, part 2– foundation kata - February 13, 2020
- Practice makes perfect, part 1 – Code kata - January 30, 2020
Use cases have become a core part of the requirements analyst’s arsenal. Used well they can bring dramatic increases in customer satisfaction and a whole host of other subtle benefits to software development.
The use case itself is very simple in concept: describe the functionality of the system in terms of interactions between the system and its external interactors. The focus of the use case is system usage, from an external perspective.
Despite this apparent simplicity, requirements analysts frequently struggle to write […]
The Baker’s Dozen of Use Cases
Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
Latest posts by Glennan Carnie (see all)
- Practice makes perfect, part 3 – Idiomatic kata - February 27, 2020
- Practice makes perfect, part 2– foundation kata - February 13, 2020
- Practice makes perfect, part 1 – Code kata - January 30, 2020
Rule 13: Say it with more than words
Use case descriptions are most commonly written in text format (albeit often a stylised, semi-formal style of writing). Text is a very effective method of describing the transactional behaviour of use cases – it’s readily understandable without special training; most engineers can produce it (although the ability to write basic prose does seem beyond the capability of many!); and it is flexible enough to deal with complex behaviours – for example, variable numbers […]
Posted in Design Issues
Tagged Analysis, Baker's Dozen, Notation, Requirements, UML, Use Cases
1 Comment
The Baker’s Dozen of Use Cases
Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
Latest posts by Glennan Carnie (see all)
- Practice makes perfect, part 3 – Idiomatic kata - February 27, 2020
- Practice makes perfect, part 2– foundation kata - February 13, 2020
- Practice makes perfect, part 1 – Code kata - January 30, 2020
Rule 12: Avoid variations on a theme
A common affliction amongst novice use case modellers (particularly those from a development background) is the desire to fettle the use case model – to organise it, revise it, balance it; and generally make it look more like a design model. Unfortunately, beyond a certain point this effort actually starts to degrade the utility and effectiveness of the model. More and more effort is put into a model that becomes less and less useful […]
Posted in Design Issues
Tagged actor, Analysis, Analysis Paralysis, Baker's Dozen, inheritance, Rule, Specialisation, UML, Use Cases
1 Comment
The Baker’s Dozen of Use Cases
Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
Latest posts by Glennan Carnie (see all)
- Practice makes perfect, part 3 – Idiomatic kata - February 27, 2020
- Practice makes perfect, part 2– foundation kata - February 13, 2020
- Practice makes perfect, part 1 – Code kata - January 30, 2020
Rule 11 – Don’t abuse «include»
A use case contains all the steps (transactions) needed to describe how the actor (our stakeholder) achieves their goal (or doesn’t; depending on the particular conditions of the scenario). Therefore a use case is a stand-alone entity – it encapsulates all the behaviour necessary to describe all the possible scenarios connected to achieving a particular end result. That’s what makes use cases such a powerful analysis tool – they give the system’s requirements context. Use […]
Posted in Design Issues, UML
Tagged Analysis, Design Case, includes, modelling, Requirements, UML, Use Case
1 Comment
The Baker’s Dozen of Use Cases
Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
Latest posts by Glennan Carnie (see all)
- Practice makes perfect, part 3 – Idiomatic kata - February 27, 2020
- Practice makes perfect, part 2– foundation kata - February 13, 2020
- Practice makes perfect, part 1 – Code kata - January 30, 2020
Rule 10: The magical number seven (plus or minus two)
Psychologist George Miller, in his seminal 1956 paper "The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information", identified a limit on the capacity of human working memory. He found that adults have the capability to hold between five and nine ‘chunks’ of information at any one time. A ‘chunk’ may be a number, letter, word or some other cohesive set of data.
What has this […]
The Baker’s Dozen of Use Cases
Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
Latest posts by Glennan Carnie (see all)
- Practice makes perfect, part 3 – Idiomatic kata - February 27, 2020
- Practice makes perfect, part 2– foundation kata - February 13, 2020
- Practice makes perfect, part 1 – Code kata - January 30, 2020
Rule 9 – Build yourself a Data Dictionary
Transactions between the actors and the system typically involve the transfer of data. This data has to be defined somewhere. If you’ve built a Domain Model ( see Part 5 – here) most of the data will be identified there; but even then the class diagram is not always the most practical place to capture the sort of information you need to record.
Another way to capture this information […]
Posted in Design Issues
Tagged Analysis, Baker's Dozen, Data Dictionary, Requirements, UML, Use Case
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The Baker’s Dozen of Use Cases
Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
He specialises in C++, UML, software modelling, Systems Engineering and process development.
Latest posts by Glennan Carnie (see all)
- Practice makes perfect, part 3 – Idiomatic kata - February 27, 2020
- Practice makes perfect, part 2– foundation kata - February 13, 2020
- Practice makes perfect, part 1 – Code kata - January 30, 2020
RULE 7: Describe ALL the transactions
A use case, as the name implies, describes the usage of the system from the point of view of some beneficiary (our Actor). It is NOT (as I seem to spend my whole life telling people) is just the system function, organised as some sort of graphical ‘sub-routine’. This means the use case description must include the expected behaviour of the actors as well as the expected behaviour of the system.
This can […]
Posted in Design Issues
Tagged Analysis, Baker's Dozen, Requirements, Transaction, UML, Use Cases
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