A conceptual example of a layered Enterprise Architecture description is presented as the first indication of the evaluation of the current state of a footfall counter service. The footfall counter service represents a city service which aims to collect the number of people in various places of a city in order to improve the environments of the city.
The figure depicts a model representation of three architectural views from a service, information and technology perspective using the Graphical Language ArchiMate. The service view presents the current users of the city service who access the information provided by the footfall-counter service. The information view presents the software platforms provided by two different software vendors Both software platforms allow users to authenticate in the system, configure a dashboard and download reports in different formats (e.g. doc, pdf, csv, etc.). The technology view presents the hardware and software infrastructure that support the city services. This view includes Database servers in a Cloud environment, gateways and smart objects (i.e. footfall-counter sensors).
The model of the current state of this city service indicates that there is a data integration issue due to the lack of a common data format. Each user downloads the information from diverse sources with different data formats what causes information silos. Information is not adequately shared but rather remains stored within each system. The stakeholders of the smart city do not perceive the real value of the information collected through this city service and the intelligent decision making is not supported properly.

Modeled Architecture

In this very simple conceptual example, we are going to model the right-side of the architecture shown in the figure above. Specifically, we are interested in the

 

Simulation Results

In this very simple conceptual example, we are going to model the right-side of the architecture shown in the figure above. Specifically, we are interested in the effect of processing power of the “Gateway” on the overall latency of the system (measured by the number of entities reached the final destination).
For demonstration purposes, we will show here two different results based on two different values of the “number of servers” property of “N-Server Gateway”. We are going to run the simulation for 100 time units, which is going to be represented as the x axe in the following figures.

 

First Run (number of servers = 2)

Average time of entities waiting in the queue to be processed Number of processed entities reached the final destination

 

Second Run (number of servers = 5)

Average time of entities waiting in the queue to be processed Number of processed entities reached the final destination

 

Analysis of the Results

As we can see, when we increased the processing power of the “Gateway” (by increasing the number of servers from 2 to 5), we achieved a waiting time of almost zero. In addition, the final number of entities reached the final destination are now linear with the time. This is just a very simple example to demonstrate how simulation can be used to evaluate architectures, specifically the dynamic properties and behavior. This example was just to show how Simulink can be leveraged for dynamic evaluation of architectures.