BT4 Session 6/6/2013 10:15 AM 

       

"Non-Pathological Software Metrics"    

Presented by:

Stephen Frein Comcast Cable

         

Brought to you by:  

  

340 Corporate Way, Suite 300, Orange Park, FL 32073 888‐268‐8770 ∙ 904‐278‐0524 ∙ sqeinfo@sqe.com ∙ www.sqe.com

Stephen Frein Comcast

Stephen Frein is a software development manager at Comcast, where his team creates tools for process automation and quality assurance. As an adjunct professor at Drexel University, he delivers soporific lectures on database development and IT management. Stephen has been leading development teams for fifteen years, and occasionally does it well, mostly by dint of accidents he cannot reliably replicate. He has presented at previous conferences by sneaking into unused rooms and deceiving the unsuspecting. Stephen enjoys polluting the hive mind via frein.com and writing vapid, self-deprecating bios.

 

Non-PathologicalNon PathologicalSoftware Metrics

Stephen FreinC tComcast

http://www.frein.comstephen.frein@gmail.com

About Me

Context MattersContext Matters

Metrics can do harm.

B f l f h Be careful of what you incentivize.

Why Measure?

ObjectivityClarity

Objectivity

Authority

What to Measure?

Productivity!

You can't do that.Quit it.

W h f bl

Stop it.-- Joel Spolsky

We have no way of reasonably measuring productivity.

-- Martin Fowler

You get what you measure.

I th t h t t?Is that what you want?

LOCLOCLines of Code

More is Better!

public Cost calculateShipmentCost(Order someOrder) {Cost shipCost = new Cost(0);if (someOrder.getTotalCost() < 25) { shipCost.setCost(10); }else { shipCost.setCost(5); }return shipCost;

} 9 LOC}

public Cost calculateTotalCost(Order someOrder) {return someOrder.getTotalCost().add(

calculateShipmentCost(someOrder).getCost() );}

public Cost calculateReturnRefund(Order someOrder) {// only half of shipping costs get refundedreturn someOrder.getTotalCost().add(

calculateShipmentCost(someOrder).getCost()/2) );}

public Cost calculateTotalCost(Order someOrder) {Cost shipCost = new Cost(0);if (someOrder.getTotalCost() < 25) { shipCost.setCost(10); }else { shipCost.setCost(5.00); }return someOrder.getTotalCost().add(

shipCost getCost() );shipCost.getCost() );}

public Cost calculateReturnRefund(Order someOrder) {Cost shipCost = new Cost(0);if (someOrder.getTotalCost() < 25) { shipCost.setCost(10); }else { shipCost.setCost(5.00); }{ p ( ) }// only half of shipping costs get refundedreturn someOrder.getTotalCost().add(

shipCost.getCost()/2 );} 10 LOC

Trade-offs

“Productivity”Maintainability ProductivityMaintainability

Change Incentives

EconomicsDrive Behavior

Don’t make a measureGoodhart’s Law

into a target.

Guess when …

This never would have happened if

i

<sarcasm>

we were using story points.</sarcasm>

Predicting the Future

“Ideal”

Metrics that focus on a proxy often

cause pathological behaviors.

PROXY GOAL

The proxy loses its connection to the intended goal.

What to do?

Balance

Test Cases Per Hour Defects Per Test Case

Stealth

Voyeurism

Independence

Metrics I’ve Tried

Truck NumberHow many ypeople can get hit by a truck before the project is in big project is in big trouble?

Customer SatisfactionWhat do your What do your customers think of your product?

Recommended:Sh rto Short

o Simpleo Anonymouso Comment box

Learning

Find the Incentives

Questions?