Chapter 3

Question 1

Predictive software development

Answer 1

has big advantages

encourages up-front design

Question 2

Preditctive software development nicknames

Answer 2

BDUF (Big Design Up Front)

Because that’s what it encourages

Question 3

Iterative model

Answer 3

You build the final application incrementally

Start with minimally viable product and then add pieces to it.

Question 4

Software engineering goals at its most fundamental

Answer 4

producing useful applications

Question 5

Iterative software development modesl

Answer 5

Unified Process and iterated waterfall

Question 6

Second goal of software engineering

Answer 6

producing software quickly

Question 7

Rapid Application Development (RAD)

Answer 7

These models incorporate some of the best features of the modesl described in preceding lessons plus new features that get results to the end user quickly

Pushed devs to generate as much high-qulaity code as possible and as quicly as possibly

Question 8

Agile method

Answer 8

allow a projects goals to change over time to track changing customer needs

Question 8

Extreme programming

Answer 8

uses pair programming to ensure that every piece of code goes through a kind of code review

Question 9

Test driven development model

Answer 9

forces programmers to write tests for their code

Question 10

Commit to the development method

Answer 10

Unless everyone commits, you’ll have trouble getting success from the model

Question 11

predictive development model

Answer 11

Predict in advance what needs to be done and then you go out and do it

– use requirements to design the system and
—- > use the system design to write the code

• test and deploy

Question 12

Problems with predictive model

Answer 12

Its hard to predict exactly wht a softwarae application needs to do and how you should build it ahead of time

– customer needs change
– if you need to learn programing technique on the fly could lengthen timeframe

Question 13

Adaptive development model

Answer 13

Allows you to change projects goals during development

You can periodically reevaluate and change your direction

Question 14

Adaptive model analogy

Answer 14

With each new development in the project you reevaluate where you are and decide if you want to keep going the same direction

Question 15

Predictive model works well when

Answer 15

the project is small

Question 16

Predictive project Success and failure indicators

Answer 16

User involvment - if the users help define the requirmeents, they’re more likelyi to be correct

Clear Vision - if the customers and developers have the same clear vision about the project’s goals, development will stay on track

Limited size - a small size helps the customers and team members see the whole picture all at once. Requirements won’t have time to change

Experienced team – experienced team members are less likely to design something they can’t build. They also won’t wander off writing code that doesn’t work out.

Realistic - if the suers ask for a telepathic user interface they’ll be disappointed

Established technology - if you stick to technology that you’ve used before you’ll udnerstand how to use it correctly

Incomplete requirements - in a predictive porject, if the requirements don’t say you should do sokmething, it won’t get done

Unclear requirements - if the customers and developers don’t all have the same vision of what the application should do, you’ll have trouble satisfying everyone.

Chaging requirmeents - the requirements are like railroad tracks: After they’re set, changing course is difficult

No resources - even if you have clear requirements and a perfect design, a single programmer can’t write a 10,000 line program in one week.

Question 17

Predictive model Advantages

Answer 17

Predictability - if everything

Stability

Cost-savings

Detailed design

less refactoring

Fix bugs early

Better documentation

Easy maintenance

Question 18

Predictive model Disadvantages

Answer 18

Inflexible – requirements can’t change, so if they need to… you’re in trouble

Later release - you can’t release anything until the project is finished (unlike an adaptive model where incremental releases can occur

Big Design Up Front - you need to defined everything up front, so you can’t start developing until you know everything you’re going to need to do.

Question 19

Pure predictive models

Answer 19

Assume each stage of development is finished completely and correctly before the next stage begins

Question 20

Predictive model / BDUF

Answer 20

one of the

Question 21

Waterfall model

Answer 21

Predictive

The plain vanilla of the predictive model world

You finsih each step completely and thoroughly before you move on to the next step

Question 22

Waterfall analogy

Answer 22

Predictive

Each step is a bucket

When one bucket is full the information floods to the next bucket (task) to complete

Question 23

Waterfall model can work well if these assumptions are satisified

Answer 23

Predictive

The requirements are precisely known in advance

the requirements include no unresolved high-risk items

The requirements won’t change much during development

The team has previous experience with similar projects

There’s enough time to do everything sequentially

Question 24

Sashimi

Answer 24

Predictive

Similar to waterfall structure, but each piece overlaps

In other words, while you’re still working on requirements other teammates can start the Design step

Question 25

Waterfall with Feedback

Answer 25

Predictive

Allows you to jump back a step if necessary in order to rework the previous step

Question 26

Advantages of Sashimi

Answer 26

1 - People wit different skills can focus on their specialties without waiting for others

2 - It lets you perform a “spike” or “deep dive” into a particular topic to learn more about it. For example, if the clients want some new type of technology added to the requirements that you are not familiar with, you can assign a team to research that while the rest of the team continues with the current requirements and moves on to the Design phase

3 - later phases can modify earlier phases

Question 27

Incremental Waterfall

Answer 27

Predictive

Uses a series of separate waterfall cascades

Each cascade ends with a usable application as a deliverable called an “increment”

Each “increment” provides more features than the previous one

It’s essentially going through a full iteration of the SDLC for each “increment”

Actually somewhat adaptive since you can reevaluate your direction at the start of each new “increment”

Question 28

V-Model

Answer 28

Predictive

Waterfall in V Shape

Concept < – Operation & Maintenance
Requirements < – Verification & Validation
Design <– Testing
Implementation

Question 29

Software Development Life Cycle

Answer 29

AKA the Application Development Life Cycle

Requirements
Design
Implementation
Verification
Deployment
Maintenance

This is a Predictive model actually…. what? I thought it was just the various steps in the life cycle

Question 30

Expanded SLDC

Answer 30

Initiation (an idea)
Concept Dev – initiator evaluates the initial idea

Preliminary planning - PM and technical Lead are assigned and start planning

Requirements

High level designs - specify major subsystems, data flow, database needs

Low level design - explains how to build the applications pieces that were defined in the high level design

Development - the team writes the program code. They perform tests all the way

Acceptance testing - customers get to test

Deployment

maintenance

Review - can the development process be improved in the future

Disposal - the application has run its course and can no longer be improved

Question 31

Iterative vs Predictive

Answer 31

Predictive models can’t make changes as easily as iterative models

Predictive models spend a lot of time in the beginning making sure you get the project right. So changing that direction after the fact is really difficult and could mean the project is a failure

Predictive models don’t do fuzzy requirements well

Iterative

Iterative modesl handle fuzzy well

They build functioning models for each cycle and then add pieces to it incrementally until the project is finished

The commitment then, is smaller, it is a smaller cycle, so changes are easy to make

Question 32

Prototype

Answer 32

A simplified model that demonstrates some behavior that you want to study

Question 33

Evolutionary prototype

Answer 33

Demonstrates the features of a an application. As the project develops you keep adding onto the features of the evolutionary prototype until the application is finished

Question 34

Throwaway prototype

Answer 34

Demonstrates one aspect of a system and then you throw it away and start coding

Question 35

Incremental Prototype

Answer 35

A collection of prototypes that separately demonstrate the applications features. Eventually you combine these prototypes to create the single application

Question 36

Benefits of prototypes

Answer 36

Common vision = customers and developers see the same preview of the finished application

Improved requirements = allow customers to see what the finished application will look like

Improved design = developers quickly explore specific pieces of the application to learn what they involve

Question 37

Disadvantages of prototypes

Answer 37

Narrowing vision
Customer impatience - if the prototype is good then the customer will think that the final application can be completed relatively quickly

Raised expectations - the prototype might demonstrate features that won’t be included in the final application

Schedule pressure - goes with customer impatience

Code Attachment - developers might become attached to code they’ve produced and become unwilling to change what they’ve written even if something better is available

Neverending prototypes - sometimes developers put too many features and spend too much time on a prototype. throwaway prototypes for example are meant to be thrown away not used as the code base for the application