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Estimating the Cost of Heterogeneous Solutions

Eltjo R. Poort, Eric van der VlietIWSM Mensura 2014

Eltjo Poort

CGI NL Lead Expert Architecture

• Reviewing Bids & Projects

• Standardising & Improving Architecture Practice in CGI NL

GGI Architecture Community of Practice lead

Researcher

• Improving Architecture Practices

• With Universities (VU Amsterdam, Twente, Eindhoven)

• Member if IFIP WG 2.10 Software Architecture

http://eltjopoort.blogspot.com

• applications

• embedded systems

• infrastructure

• SOA implementation

• systems integration

• outsourced services

• ...

Metrics-based estimation techniques assume homogeneity

Enterprise-level Solutions are Heterogeneous

4

Solution-Based EstimatingCGI’s approach to estimate heterogeneous solutions

• Break down solution into homogeneous components

• Use Solution Architecture as basis

• Strong involvement of Solution Architect in estimating process

• Document Solution Architecture in Costing View

5

Impact of Architecture on Project ControlQuantified by research*

Result Improvement by applying Solution Architecture

Budget predictability 2-3 x better Std dev 32 13

Budget overrun 7 x less 22% 3%

Time overrun 6 x less 48% 8%

Troubled projects 3 x less 38% 13%

Customer satisfaction 1-2 points better 10 point scale

Results delivered +10%

*Survey among 49 software development projects between €50,000 and €2,500,000. Reported by Raymond Slot, PhD Thesis, 2010.

Specifically correlated with presence of architect and defined solution architecture during budget calculation

SBS: deliverable-oriented hierarchical decomposition of the solution

The SBS is a tree showing how the solution decomposes into products

• top level of the tree is the Solution itself

• lower levels show how each product breaks down into sub-products, etc.

Solution Breakdown Structure (SBS)

Smart Phone

Hardware Software PackagingMarketing

plan

Control system

Camera

User interface

Casing

Hardware

Prototype

Control sw

Camera sw

User interface sw

Control system

Camera

User interfaceHardware

Single box for phone

Multi pack for shipping

Marketing plan

TV Commercial

Trade show exhibit

Depth of the tree: level of detail required for a reasonable cost estimate

Criteria for lowest level products:

• Single delivery organization (team, supplier, …)

• Homogeneity for metrics-based estimation

Solution Breakdown Structure (SBS)

Smart Phone

Hardware Software PackagingMarketing

plan

Control system

Camera

User interface

Casing

Hardware

Prototype

Control sw

Camera sw

User interface sw

Control system

Camera

User interfaceHardware

Single box for phone

Multi pack for shipping

Marketing plan

TV Commercial

Trade show exhibit

Solution-based estimatingCollaboration

Solution Architect

Business Issue

Funct Reqs

NonFunct Reqs

Targeted Solution

SBSArchitecture

EstimatingEffort

Project/Delivery Manager

WBS ScheduleDeliveryStrategy

Cost Engineer

Costingmodel

BusinessOwner

Pricingmodel

FinancialEngineer

Financialmodel

All architecture documentation methods use views

• ISO 42010, TOGAF, Archimate, 4 + 1, ‘Views and Beyond’

• Viewpoints address concerns per stakeholder (group)

CGI’s architecture templates include Delivery Breakdown view

• Specific view for stakeholders with Cost concerns

• Includes Solution Breakdown Structure

Architecture DocumentationViews and Viewpoints

10

Comparison with other approaches

• Use of architecture operationalizes impact of Non-Functional Requirements (NFRs)• NFRs are key architectural drivers

• Metrics-based approaches include NFRs in “complexity factor” (only re-usable between comparable architectures)

• SBE includes non-software & off-the-shelf components

• Solution Breakdown Structure based on PRINCE2’s PBS

COCOMO®

Solution Based EstimationSummary• Architecture and estimation strongly related

• SBE: structured way to link heterogeneous architectures to cost

• Preliminary evidence suggests positive impact:• Better scope definition more detailed underpinning of estimate

• Improved understanding impact of solution on planning & budget

• Enhanced traceability between cost and (non-)functional requirements

• Better consolidation of partial estimates

Spare slides follow

Solution DefinitionDocument Template for Planning/Budgeting/Bid stage

1 Introduction2 Requirements2.1 Business drivers2.2 Key functionality2.3 Key architectural requirements2.4 Other architectural drivers3 Key Design Decisions and Concerns4 Operational View4.1 Solution in its operational environment: Context Diagram4.2 Operational decomposition5 Delivery Breakdown View5.1 Solution Breakdown Structure5.2 Delivery Strategy

Development Approach

Development Approach: high-level activities required to develop or otherwise obtain the products that make up the solution

Responsibility for selecting delivery approach lies with Project/Delivery Manager

• but consult Solution Architect to make sure of proper fit with solution's structure and requirements

Integration Strategy

Integration Strategy: describes how the various products in the SBS are integrated to form the complete solution

Responsibility for determining integration strategy lies with Project/Delivery Manager

• but consult Solution Architect to make sure all architectural concerns regarding the implementation are addressed