Estimating the requirements determination of a project

The Business Basis for
Software Requirements
and
Estimating the
Requirements Determination Portion
of a
Product Development Project

By Harry F. Gilbert
http://www.hfgilbert.com

Copyright © 2010 Fish, Gilbert & Associates, LLC, All Rights Reserved http://www.hfgilbert.com.

Purposes

• Provide a solid understanding of the business basis
for requirements, and,
• How to estimate the time and resources needed to
conduct the requirements determination phase of a
software development project.
• While primarily focused on software development,
the concepts here are applicable to the development
of any product, not just software.


Getting it Wrong


Formal requirements come from three sources

Level 3:
Product
What developers
need to build

Level 2:
User What users will be able
to do with the product

Level 1:
Market Business
Why the project
is being undertaken
from a business perspective


Context of Requirements Determination Estimating

Why is requirements estimating performed?
• Respond to a request for estimate
• Help client to define the scope of a project
• Define resources, skills, and effort
• Fit schedule and resource availability


Context of Requirements Determination Estimating

When is estimating performed?
• Pre-planning
• Response to request
• Negotiations
Limits of the estimate:
• Covers only the requirements determination part
of a development project
Plan Requirements
Determination
Define

Design

Construct

Test

Deploy

Maintain Retire


Requirements Determination and the Systems Life Cycle Requirement
Determination
Work from the abstract to the concrete:

Scope W

Estimate H Understand
Y
the
problem
High-Level (Business) Requirements

W
H
Detailed (System) Requirements A
T

Design
Construct H Solve
Test O
W
the
problem
Implement….


Understanding the Scope Statement

Scope Statement
Scope Statement
Industry
Business
Process and
Data Objectives Identifies the key business
Frameworks
features of the proposed
Business
Functional
solution, and the systems,
Process
Diagrams Summary
agents and organizations
which define the boundaries
Feature
Set
for the solution.

Interfaces to
External This is the scope of the solution
Environment
Context rather than the project scope.
Diagrams
Interfaces
within
Client
Environment


Understanding High-Level Requirements

Business Requirements

Business
Business (High-Level) Requirements
Requirements
A collection of statements that
identify the breadth of what a
User
Requirements Initial solution must provide in order to
Use
Case meet the business needs.
ID,
System Summary,
Interface Actor List,
Requirements Diagrams
Provides an overview of end-to-end
Functional business activities, identification
Requirements
of functions and interfaces,
applicable business policies,
Business Identify
Business
and non-functional constraints.
Policies
Rules

Non-Functional
Requirements
(Constraints)

Conceptual Enhancement or support
Business projects may have logical
Data Model data models available at
this level also


Information Flow within Requirements Determination

Scope Statement Business Requirements System Requirements
Industry
Business Business
Process and Functional
Data Objectives Requirements
Requirements
Frameworks

Business User
Process Functional Requirements Initial User
Diagrams Summary Use Requirements
Case
Estimate ID,
Use
Cases
System Summary,
System
Feature Interface Actor List, Interface
Set Requirements Diagrams Requirements

Functional
Business
Requirements
Rules
Interfaces to
External
Environment
Context Identify Non-Functional Requirements (Constraints)
Business
Diagrams Policies Business
Interfaces Rules
within Quality Security
Client Attributes Requirements
Environment
Non-Functional
Requirements
(Constraints) Performance Safety
Requirements Requirements

Conceptual Enhancement or support
Business projects may have logical Logical
Data Model data models available at Business
this level also Data Model


How to estimate requirements time and resources

• Estimating the requirements
determination phase of a
development project is an iterative
process
• It requires cooperative interaction
between the client, the project /
program management, and the
requirements determination team


Estimating Requirements Determination Activities

The estimate can not and does not include:
• Tasks outside of requirements determination
• Work performed by 3rd party suppliers
• Impact of resource unavailability *
• Impact of quality or availability of documentation not
meeting commitments*
• Changes to overall scope after project is initiated*
• Changes to complexity discovered during the
requirements determination work sessions*

* These items are handled via change request


Critical Success Factors for Accurate Estimates

• Defined business goals, context, and rationale.
• Functionally decomposed business model.
• Analysis of functional complexity.
• Skilled, trained RD team following process and
methodology.
• Committed SMEs and stakeholders providing business,
regional, user, and technical knowledge.
• Participants have adequate time for preparation and
participation to follow planned work session schedule.
• Adequate physical / communication facilities.
• Regional and cultural issues are considered.
• Quality is built into the requirements determination
process, not “inspected in” afterward


Functions

Decompose the project scope into functions
• A function designed to perform a business purpose
• What something is used for, how it is expected to perform.
• A not-yet-formalized requirement, or set of requirements.
• Functions must align to business goals and objectives.
• Example:
Functions such as “Provide Payments to Contractors” and “Enable
Schedulers to Estimate and Schedule Jobs” should align with one or
more business goals such as “Provide Accurate Estimates for
Prospective Customers,” or with an objective such as “Ninety Percent
of All Estimate Requests will result in a Scheduled Job.”


Features

Functions decompose into features
• Features are the characteristics and implementation details
of functions
• Features align to functions
• They are based on user requirements, business rules,
constraints, and quality attributes*
• Features determine the complexity of functions

* Non-functional requirements used to evaluate the performance of a system.


Deriving Functions from a Scope Statement

“We need to allow schedulers to be able to
Statement assign contractors to jobs within the
contractor’s local area”

• Maintain a list of authorized schedulers
• Add, View, Edit, Report
• Maintain a list of authorized contractors and the
Functions
contractor’s location and area of operation
• Browse, View, Query, Add, Edit, Status,
Report, Define area of operation
• Maintain a list of jobs and the area in which the job is
Features
performed
• Browse, View, Query, Add, Edit, Status,
Report


Where to obtain information for Plan & Define estimates?

• Preliminary discussions
• Discussions with customer and Subject Matter
Experts, which lead to a Project Profile
• Context and Business Process Model diagrams
• Existing requirements documentation
• Existing system documentation
• Decomposition of existing screens
• Service Request documentation
• Project Charter
• Project Description
• Question and response documents
• Detailed requirements estimating negotiations


Business Process Modeling

Operational Definitions

Process: A series of activities with a defined deliverable
(Example: the goal of a Sales Process is a signed contract)
Activity: A sub-process, function, or objective within the process
(Example: Identify a potential customer)
Task: A component of an activity
(Example: Establish creditworthiness)
Step: An action taken to accomplish a task
(Example: Look up the credit history)

• A business accomplishes its goals and needs through processes.
• A process consists of activities assigned to resources
• Resources perform tasks (consisting of steps).

Business Need Processes Activities Tasks


Business Process Decomposition

Business 1. Produce 2. 3.
& Deliver
Needs Product

1.1. Plan & 1.2. Convert 1.3.
Processes Acquire Resources to
Resources Products

1.1.1. Obtain 1.1.2. 1.1.3.
Activities Materials & Schedule
Supplies Production

1.1.1.1. 1.1.1.2. 1.1.1.3.
Tasks Complete Send
Purchase Order to
Order Supplier
Steps…..

Multi-Level and End-to-End Business Process Models

Level 2

Level 3 Level 1

Multi-Level and End-to-End Business Process Models


Cli
Sales Process – page 1 of 2 ent
E xam
New Incremental ple
Business Business
1 2 3 4
Identify Contact Attract Develop
Customer Customer Interest Interest
1.1 Gather contact 2.1 Call account executive 3.1 Determine customer 4.1 Determine customer
information for account 2.2 Call sales executive audience audience
and sales executives 3.2 Assemble presentation 4.2 Assemble presentation
and customer 2.3 Provide follow-up
information (e.g., service team team
1.2 Gather customer line portfolio) 3.3 Give Level 1 4.3 Prepare demonstration
information presentation. Marketing materials and
2.4 Educate and coordinate
1.3 Determine sales activity with account and reviews presentation equipment (if needed)
approach sales executives 3.4 Provide follow-up 4.4 Give Level 2
1.4 Review & track. 2.5 Send customized contact information (e.g., further presentation, detailed
letter to customer. offerings detail, preview presentation, and / or
Marketing reviews letter material for next demonstration.
presentation) Marketing reviews
2.6 Call customer presentation /
3.5 Review & track. Inform
2.7 Provide follow-up account, marketing, demonstration
information (e.g., sales, and support 4.5 Provide follow-up
brochures, etc.) organizations of information (e.g.,
2.8 Review & track. Inform presentation results contact information,
account, marketing, (Stop or Continue) meeting schedules)
sales, and support 4.6 Review & track. Inform
organizations of contact account, marketing,
results (Stop or sales, and support
Continue) organizations of
presentation results
(Stop or Continue)
For immediate For immediate
opportunities Proceed opportunities Proceed
to Identify Opportunity to Identify Opportunity


Cli
Sales Process – page 2 of 2 ent
E xam
ple
Renewal
Business
5 6 7
Identify Pursue Close
Opportunity Opportunity Sale
5.1 Support and delivery 6.1 Pursuit team meets and 7.1 Delivery team identified
organizations meet and follow-up with customer 7.2 Business Partner
follow-up with customer to define opportunity Agreements are
to identify opportunities (repeat as needed) formalized between
(repeat as needed) 6.2 Account, marketing, account and delivery
5.2 Account, marketing, sales, and support organizations
sales, and support organizations produce 7.3 Delivery team leaders
organizations prioritize proposal for customer. meet with customer to
identified opportunities Marketing reviews define project and
(Stop or Continue) proposal develop Statement of
5.3 Pursuit team is 6.3 Delivery organizations Work, if necessary
organized to further are notified of potential (repeat as needed)
define opportunity for staffing requirements 7.4 Customer signs
proposal development and availability date Statement of Work, if
5.4 Review, document & 6.4 Respond to customer necessary - delivery
track. Inform account, inquiries and requests begins
marketing, sales, and for further information 7.5 Account establishes
support organizations of 6.5 Assist customer with billing arrangements
identified opportunities purchasing process with customer
requirements and 7.6 Review, document &
responds / negotiates as track. Inform account,
needed marketing, sales, and
6.6 Review & track. Inform support organizations of
account, marketing, deal results
sales, and support
organizations of pursuit
status. (Stop or
Continue)


Project Profile

A formal set of interview
questions asked to
better understand the
purpose of a project


Project Profile

Can be created pre- or post-Service Request


Cli
ent
E xam
Extract from Project Charter and Scope Documents ple

PROJECT SCOPE
PROJECT SCOPE
This project will determine best practices and products to develop aaproduct
This project will determine best practices and products to develop product
track and trace application that meets the global requirements of each user
track and trace application that meets the global requirements of each user
region (Asia Pacific, North America, Europe) in our corporation. This
region (Asia Pacific, North America, Europe) in our corporation. This
includes manufacturing, assembly, and co-located joint venture and supplier
includes manufacturing, assembly, and co-located joint venture and supplier
operations.
operations.
The system architecture will be scalable in design to support both low and
The system architecture will be scalable in design to support both low and
high volume plants.
high volume plants.
The system interfaces will be required to meet the needs of both in plant and
The system interfaces will be required to meet the needs of both in plant and
off-site manufacturing operations. The reporting toolbox will be compliant
off-site manufacturing operations. The reporting toolbox will be compliant
with Quality and Engineering business owner requirements to track local,
with Quality and Engineering business owner requirements to track local,
regional and global common parts from birth to end-product fielding.
regional and global common parts from birth to end-product fielding.


Cli
ent
E xam
Extract from Project Charter and Scope Documents ple

PROJECT OBJECTIVES ––Business Functionality
PROJECT OBJECTIVES Business Functionality
Design aasoftware application that supports one global business process for shipping zero defect
Design software application that supports one global business process for shipping zero defect
parts. These plan and define efforts shall include but not limited to:
parts. These plan and define efforts shall include but not limited to:
1.Build aaset of manufacturing quality requirements in accordance to be approved by the Corporate
1.Build set of manufacturing quality requirements in accordance to be approved by the Corporate
Manufacturing Committee
Manufacturing Committee
2.Build aaset of manufacturing quality requirements in accordance with Corporate Quality
2.Build set of manufacturing quality requirements in accordance with Corporate Quality
Procedures. These plan and define efforts should include but not limited to:
Procedures. These plan and define efforts should include but not limited to:
a. Trace quality data for all corporate-made components.
a. Trace quality data for all corporate-made components.
b. Trace the following quality on-site manufacturing operations: load, unload, component
b. Trace the following quality on-site manufacturing operations: load, unload, component
marriage points, component divorce points, scrap, rework, hot test, cold test, racking,
marriage points, component divorce points, scrap, rework, hot test, cold test, racking,
storage, shipping.
storage, shipping.
c. Trace manufacturing operations performed off-site of the plant
c. Trace manufacturing operations performed off-site of the plant
d. Trace storage locations both plant on-site and off-site
d. Trace storage locations both plant on-site and off-site
e. Trace manufacturing process operations performed off-site
e. Trace manufacturing process operations performed off-site
f.f.Trace supplier in-bound material. This requirement is dependent on global labeling
Trace supplier in-bound material. This requirement is dependent on global labeling
standards and therefore may remain as aarequirement for future execution.
standards and therefore may remain as requirement for future execution.
g. Create business case for trace functionality at casting plants.
g. Create business case for trace functionality at casting plants.
h. Traceability of software versions used in the product
h. Traceability of software versions used in the product
3.Capability to support stand alone manufacturing plants or those manufacturing plants collocated
3.Capability to support stand alone manufacturing plants or those manufacturing plants collocated
with assembly operations
with assembly operations


Cli
Extract from Customer Overview Diagrams ent
E xam
ple
Track and Trace Program Overview

Production
Load Test
ECV/
Button Up
Inventory
Flow -

Repair
Out Loop In

• Traceability of software versions in all
modules as shipped Expanded
• Expanded traceability to support off line
Care traceability by
processing
and WinTerm
lot number
• Traceability of purchased parts Rack
Shipping
Plant Configuration Data & Reporting
Expanded containment
capability for internal
CDM
Expanded traceability of common
or commercial
products across regions
customers
WinTerm
Report Admin.

• Support of shipping processes for delivery
off or on campus
QUALITY • Expanded traceability for off-site locations

•Campaign Manager
•Repairs & Quality Gates
CDM •Export and Import Serial Numbers
•Retrieve Serial Number History


Cli
Extract from Customer Overview Diagrams ent
E xam
ple
Functional
Functions
Production
Load Test
Groupings
ECV/
Button Up
Inventory
Traceability of software version in
Flow -
all module as shipped
Repair
Out Loop In Expanded traceability to support off-line
processing
• Traceability of software versions in all
modules as shipped Traceability of purchased parts
Expanded
Care
• Expanded traceability to support off line
and Traceability of common products across by
WinTerm
traceability
processing Traceability Rack lot number
• Traceability of purchased parts regions

Shipping
Traceability by lot number
Expanded containment capability for
Plant Configuration Data & Reporting internal or commercial customers
Expanded containment
Support of shipping processes for deliver
on- or off-campus capability for internal
CDM
Expanded traceability of common
or commercial
products across regions Expanded traceability for off-site
customers
WinTerm
locations
Report Admin.
Quality Quality functions

Global Multi-lingual / global support
• Support of shipping processes for delivery
Reporting Expanded reporting capability
off or on campus
QUALITY • Expanded traceability for off-site locations
Analysis of Vendor Capabilities
•Campaign Manager Comparison to project requirements
COTS Analysis
•Repairs & Quality Gates
CDM •Export and Import Serial Numbers COTS vendor short-list selection
•Retrieve Serial Number History


Cli
ent
Extract from Existing or Prototype Screens E xam
ple

Plant Overview


Prioritizing Functions

• Prioritization is essential to successfully estimate
requirements determination activities.
• Prioritization is the process of assigning a
precedence that orders or ranks one function or
requirement over another.
• Prioritization allocates resources to the most
important requirements and facilitates making
decisions about which to implement and when to
implement them.


Prioritization Benefits

• Helps stakeholder focus
• Surfaces trade-offs among competing project
goals
• Minimizes politics and personal biases
• Improves communications
• Creates stakeholders buy-in
• Control scope creep
• Framework for ongoing prioritization
• Plan software releases


High-level overview of requirements estimating process

1. Work with the scope statement, process models, other
documentation, and the customer to get a reasonably clear
idea of the project
2. Break the solution down into functional groups, component
functions and the complexity of each (features)
3. Prioritize the functionality (at this point requirements not
uncovered)
4. Consider cultural and environmental issues, and the
knowledge and availability of participant stakeholders
5. Consider the skills needed to do the requirements
determination
6. Estimate the raw effort hours needed to elicit and document
the requirements
7. Adjust the raw effort hours for cultural and environmental
factors
8. Calculate the man-hours based on resourcing
9. Calculate calendar time based on schedules, and cost
10. Iterate, negotiate.

Quality / Availability of Business Process Models


Cli
ent
Estimating Functional Requirements E xam
ple
Functional
Functions
Groupings
Traceability of software version in
all module as shipped

Expanded traceability to support off-line
processing
Traceability of purchased parts
Traceability of common products across
Traceability regions
Traceability by lot number
Expanded containment capability for
internal or commercial customers
Support of shipping processes for deliver
on- or off-campus
Expanded traceability for off-site
locations
Quality Quality functions

Global Multi-lingual / global support

Reporting Expanded reporting capability
Analysis of Vendor Capabilities

COTS Analysis Comparison to project requirements

COTS vendor short-list selection


Cli
ent
Estimating Functional Requirements E xam
ple

Business
Functional Use External Business Quality Business System
Functions Complexity Need BPM
Requirements
Groupings Cases Interfaces Rules Attributes Requirements Requirements
Traceability of software version in engine M Yes 1 1 3 3 3 5
or transmission module as shipped

Expanded traceability to support off-line M Yes 1 1 3 3 3 5
processing
Traceability of purchased parts M Yes 1 5 3 3 3 5
Traceability of common products across M Yes 1 3 3 3 3 5
Traceability
regions
Traceability by lot number M Yes 1 1 3 3 3 5
Expanded containment capability for M Yes 1 5 3 3 3 5
internal or commercial customers
Support of shipping processes for deliver None No 0 0 0 0 0 0
on- or off-campus
Expanded traceability for off-site None No 0 0 0 0 0 0
locations
Quality Quality functions M Yes 1 0 3 3 3 5
Global Multi-lingual / global support M Yes 1 0 3 3 3 5
Reporting Expanded reporting capability H Yes 1 2 5 5 5 10
Analysis of Vendor Capabilities None No 0 0 0 0 0 0
COTS Analysis Comparison to project requirements None No 0 0 0 0 0 0
COTS vendor short-list selection None No 0 0 0 0 0 0
Standard Nonfunctional From Nonfunctional Tab 15 0 0 0 15 15 15 45

Complexity = Number and Complexity of Features such as screens,
reports, calculations, rules, constraints

Estimating Non-Functional Requirements

Non-functional requirements do not directly address a
client business or application need. They address:
A property the end product must possess, such as safety or availability
The standards by which it must be created
The supporting structure that makes it possible
The architecture or regulatory environment in which it must exist


Estimating Non-Functional Requirements

NF Requirement


Estimating Resource Requirements



Resource
Skills



Planning



Business
Process
Modeling



Preparation



JAD



Requirements
Management
Entry



Quality
Assurance



Revision



Process
Delay



Resource
Source


Environmental Correction Factors


Number of JAD Participants


Location of Work Sessions


Languages spoken


Cultural Considerations


Quality of Existing Documentation


Customer / SME Knowledge


Number of 3rd Party Vendors


Prototyping / Visualization part of RD Activities


Number of User Locations


Number of Supporting Locations


Number of Impacted Customer Groups


Number of Impacted Vendor Groups


Working Session (JAD) Working Environment


Estimate Summary


Review

• It is necessary to understand the underlying business need
in order to estimate and gather good requirements with
which to satisfy the underlying business need.
• In order to obtain quality results, the requirements
determination and estimating activities need to follow solid
processes and methodologies.
• It is possible to estimate the time and resources needed for
the requirements determination phase of a development
project.
• While primarily focused on software development, the
concepts presented here are applicable to the development
of any product, not just software.


Questions

Harry F. Gilbert
harry@hfgilbert.com
http://www.hfgilbert.com


Estimating the requirements determination of a project

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