Architectural-"ilities"

What is an "Ility" you might ask? Well, there are all kinds of ilities in the context of software architecture. Here is a list of some of the most important, and calls out some of the ways to measure them.

Characteristic Category	Composite-ility	ility	Measure
Operational Architecture	Performance		Cumulative average response time - trigger alert when the average response times within a particular context exeeds 1400 ms) Maximum Response Time - Trigger alert anytime max response time of selected requests exceeds 2000ms Cumulative averge response time - trigger alert if response times continues to increase over 2 month period Double Exponential Smoothing Alert tuning Fitness function
	Scalability
	Elasticity
Quality Architecture	Reliability	Fault Tolerance
		Availability	(E[uptime])/(E[uptime]+E[downtime]) Using the nines chart
	Agility	Deployability	Measure & track the number of actual hours spent to deploy Measure & track failed deployments or errors resulting from deployment Measure & track frequency of deployment Measure errors/failures
		Modularity
Internal Quality Architecture		Component Coupling	(tight -> loose coupling) Pathological coupling External coupling Control coupling Data coupling
		Abstractness	Sum (abstract elements) / sum (concrete elements)
		Instability	Efferent coupling / efferent coupling / afferent coupling Distance from the main sequence d=|abstract+instability −1 |

Component	Modularity Maintainability Testability Availability Deployment Reliability Scaleability Evolutionary/migration-ability
Complexity/WMC	Maintainability Testability Reliability
Coupling (CE, CA, CT)	Modularity Maintainability Testability Availability Deployment Reliability Scalability Evolutionary/Migration-ability
Inheritance depth (DIT)	Modularity Maintainability Testability Deployment Reliability Evolutionary/Migration-ability
Percent