Modelling. Part 1

Models as an effective tool for business analysis


Model building is an important part of the business analysis process.

What are the models required for?

They help to describe a complex system distinctly, to show the relationship between the requirements, to focus on their important aspects, to visualize and to present them equally to all the parties that are involved in the development process.

A correctly constructed model doesn’t provide an opportunity to explain the system or process that it describes ambiguously, and also it helps to identify "blank spots" in the requirements and the processes and to develop a general structure of the system.

What models exist?

You should start with the definition of the subjects that you want to display with the help of the models. And they are the modelled entities. They can be the following:

  • Custom classes and roles;

  • Events;

  • Entities and connections;

  • Processes;

  • Rules.

And then, according to the type of the modelled entity, you will use this or that model. However, there is a large number of them. For example:

  • Data flow diagrams (DFDs);

  • Dialog maps;

  • Process flow diagrams such as swimlane diagrams;

  • Tables of events and reactions;

  • State-transition diagrams (STDs) and state tables;

  • Decision tables and decision trees;

  • Feature trees;

  • Activity diagrams;

  • Use case diagrams;

  • Entity-relationship diagrams (ERDs).

And many, many others ...

How to choose the right model?

The choice of the model depends on the type of information that you want to display, analyze or identify.

It is very important to focus on the most problematic, dangerous or uncertain parts of the system while modelling.

The candidates for modelling should be the elements that influence on the fulfillment of the most important tasks, on which the protection and security of the system depends. That is all those elements, which consequences of defects will be especially severe.

A fast choice of the model you need comes with experience: the more you meet different kinds of diagrams and apply them in your projects, the faster the experience will come and you will quickly and accurately know, which model will help you most of all. And before the time this experience comes, you can order modelling from an experienced mobile application development company or be guided by various books about business analysis and modelling, which will help you in the choice of the right model.

How to build a model?

Modelling, as well as programming, has its own languages, which must be studied before starting the construction of models. Each modelling language has its own notation. That is a notation system, which makes it universal and understandable for all the participants of the project. Each notation includes a lot of symbols, which are used to represent the concepts and their relationships (which makes up the alphabet of notation), as well as the rules of their usage, which must be followed. Otherwise, the idea of ​​unification of the data representation for all the participants of the process will be lost.

The most popular notations are the following:

  • Basic Flowchart, Cross Functional Flowchart;

  • UML (Unified Modeling Language);

  • BPMN (Business Process Management Notation);

  • Gane-Sarson Notation / Yourdon Notation (Data Flow and Context Diagram);

  • DSL;

  • SysML;

  • GUI modeling.

When can we omit the modelling?

The modeling process can be omitted in the following cases:

  • The solution is simple to implement;

  • The decision is fully understood by all the participants and the stakeholders;

  • The solution is intended for a small group of people;

  • The scope of the solution is permanent;

  • The requirements are mostly non-functional, which are difficult to visualize by models;

  • A representation in the form of a model is more complex and less understandable than a conventional text.

Read more about the models in our next articles!