Tracking Technical Debt — An Exploratory Case Study

Yuepu Guo, Carolyn Seaman

Information Systems Department, University of Maryland Baltimore County, USA

Rebeka Gomes, Antonio Cavalcanti, Graziela Tonin, Fabio

Q. B. Da Silva, André L. M. Santos, Clauirton Siebra

CIn/UFPE - Center of Informatics at Federal University of Pernambuco, Brazil

ICSM 2011

Williamsburg, VA, USA

May 25 – May 30, 2011

Technical Debt

Delaying software maintenance tasks for short term gain but possible long term cost

Risk – additional cost (interest) and uncertainty of interest payment

Decision – what technical debt should be paid off and when?

Management Practice

IMPLICIT technical debt management

Experience-based decision making (no rigorous measurement)

Proposed Research

Cost-benefit relationships of incurring technical debt

Costs and benefits of EXPLICIT technical debt management

Retrospective study

Research Questions

How and to what extent technical debt affects software projects?

Is the decision simulation is effective to uncover the benefits of explicit technical debt

management?

Introduction

2

Larger Research Project

Measuring and Monitoring Technical Debt

Technical Debt Management Framework

Background

3

TD List

TD Identification

TD Measurement

TD Monitoring

ID 20

Date 7/18/2009

Responsible Rose Angel

Type Documentation

Location Module S

Description In the last release, function F was added to

module S, but the documentation has not

been updated to reflect this change.

Principal 3.5 person-day

Interest Amount: 1.5 person-day

Interest Probability 40%

System Software application from a multi-national company

Client solution for Microsoft Exchange Server

63,218 LOC and over 5 years of evolution with 20 developers involved

Evolution

D1: Decision to maintain WebDAV communication protocol

D2: Decision to couple persistence and communication layers

D3: Decision to upgrade to ActiveSync communication protocol

R1: First system release

R2: Second system release

Technical Debt Item Delayed change of the communication protocol (T1)

Subject Technical Debt Item

4

2011

CostX

D 2R 1

D3R 2

D1: Decision to maintain WebDAV protocolD2: Decision to coupple persistence and communication layersD3: Decision to support MS Exchange 2007R1: First system releaseR2: First maintenance release

D 1

Measurement Technical debt item (T1)

Principal: Effort to switch to ActiveSync (new protocol)

Interest Amount: Rework effort on affected modules

Interest Probability Coupling the communication and persistence layers

Switching to ActiveSync

Impact of T1 Gain: Principal

Loss: Interest Amount × Interest Probability

Decision Simulation Process

Methodology

5

Track TD item at D1

Estimate principal and

interest

Simulate decision

Compare decisions

Decisions

Simulated Cost/Benefit Analysis

Results

6

507 507 507

65

585

929

0

200

400

600

800

1000

D1 D2 D3

Lab

or-

hour

Decision Point

Beneift

Cost

Defer Actual

Decision

Simulated

Decision

D1 D2 D3

Pay

Defer Defer

Pay Pay

The value of explicit

technical debt management

Defer Defer

Pay Pay

Technical debt may have significant impact on software projects (tripled the development cost in this case)

A decision made without careful analysis could aggravate the negative effect of technical debt

Explicit management of technical debt could prevent high cost incurred by technical debt

Decision simulation provides an effective approach to the technical debt problem

Business factors Real benefit of incurring the technical debt

Over-simplicity of the approach

Multi-disciplinary team

Conclusion

7

Questions?

8