Unit 4 · Session 2
Software Acquisition and Programming Languages
Today's focus
- How Software is Acquired: Build vs. Buy
- An Introduction to Programming Languages
🎯 Learning Objectives
By the end of this session, you will be able to:
- ✅ Compare buying (COTS) and building (custom) software, including their pros and cons.
- ✅ Define open-source software and SaaS.
- ✅ Define a programming language and its purpose.
- ✅ Differentiate between low-level and high-level programming languages.
- ✅ Explain the role of a compiler and an interpreter in executing code.
How Software is Acquired: Build vs. Buy
The Core Decision: Build vs. Buy
When an organization needs new software, it faces a fundamental choice:
BUILD 🛠️
Create a custom solution from scratch.
BUY 🛒
Purchase a ready-made product.
This decision impacts cost, time, and how well the software meets your specific needs.
Option 1: Buy It 🛒
Commercial Off-the-Shelf (COTS)
Definition: Pre-existing software purchased from a commercial vendor, designed for a general audience.
Think of it like buying a car from a showroom. You choose from existing models.
Examples: Microsoft Office, Adobe Photoshop, SAP ERP.
Spot the COTS! Quick Quiz
Click all COTS (Commercial Off-the-Shelf) software, then check your answers:
COTS: Advantages vs. Disadvantages
Advantages 👍
- Lower Upfront Cost: Cheaper than building.
- Faster Implementation: Ready to deploy quickly. ⚡
- Reliability: Well-tested by many users.
Disadvantages 👎
- Imperfect Fit: May not meet all specific needs.
- Lack of Control: Dependent on the vendor for updates and support.
Option 2: Build It 🛠️
Custom Development
Definition: Creating a new software application from scratch, tailored to an organization's exact specifications.
This is like hiring an architect to design and build a custom house just for you.
Custom: Advantages vs. Disadvantages
Advantages 👍
- Perfect Fit: Designed for your exact needs. 🎯
- Total Control: You own the code and can make any changes.
- Flexibility: Can evolve with your business.
Disadvantages 👎
- High Cost: Very expensive upfront.
- Time-Consuming: Can take months or years.
- High Risk: Projects can fail or go over budget.
Build vs. Buy Decision Calculator
Adjust sliders to describe your organization's situation and get a tailored recommendation:
📊 Build vs. Buy: At a Glance
Factor
Cost
Time
Fit
Control
Buy (COTS)
Low
Fast
General
Low
Build (Custom)
High
Slow
Perfect
High
Key Trade-off: You are usually trading perfect fit & control for lower cost & faster speed.
3-Question Decision Guide
Answer 3 quick questions to find the right acquisition strategy:
Beyond Build vs. Buy
The choice isn't always black and white. Two other popular models have emerged:
Open-Source Software
The "community-built" option.
Software as a Service (SaaS)
The "rental" or subscription option.
🔍 Other Methods: Open-Source Software
Definition: Software whose source code is freely available for anyone to use, inspect, modify, and distribute.
- The software itself is free, but you might pay for support, customization, or implementation.
- Examples: Linux OS, Apache Web Server, Firefox Browser, WordPress.
🔍 Other Methods: Software as a Service (SaaS)
Definition: A subscription-based model where software is hosted by a vendor and accessed over the internet.
- You don't own the software; you "rent" it.
- Usually a monthly or annual fee.
- Examples: Google Workspace, Salesforce, Microsoft 365, Dropbox.
Software Type Sorter
Click a software name, then click the correct category bucket to place it:
COTS
Custom Build
Open-Source
SaaS
🎬 Open Source vs Closed Source
Practical Application: Scenario
Case Study: A Trekking Company in Pokhara, Nepal
A new trekking agency needs software to manage bookings, guides, and customer information. What should they choose?
- Buy (COTS): Purchase a generic tour operator software. (Fast and cheap, but might not handle unique Nepali trekking permits well.)
- Build (Custom): Hire a Kathmandu-based dev team to build a perfect system. (Ideal fit, but very expensive for a new company.)
- SaaS: Subscribe to a cloud-based booking system like FareHarbor. (Low upfront cost, but ongoing fees and less control.)
- Open-Source: Adapt a free open-source CRM like Odoo. (Free software, but requires technical skill to set up and maintain.)
Nepal Business Scenario Quiz
Key Takeaways
- The "Build vs. Buy" decision is a fundamental choice in IT strategy.
- COTS (Buy) is fast and cheap but offers less flexibility.
- Custom (Build) provides a perfect fit but is expensive, slow, and risky.
- Open-Source and SaaS are popular alternatives that offer different models of cost and ownership.
An Introduction to Programming Languages
What is a Programming Language?
A programming language is a formal language with a set of instructions used to create software programs and implement algorithms.
Think of it as a special vocabulary and set of grammar rules to communicate with a computer.
Analogy: A programming language is like a recipe. The ingredients and steps (the code) must be written in a language the chef (the computer) understands to produce a final dish (the output).
Activity: The Recipe Analogy
Match each recipe component to its programming equivalent. Select from the dropdown and press Check.
| Recipe Component | Your Answer | |
|---|---|---|
| The recipe book — the rules and vocabulary | ||
| The written recipe — your specific instructions | ||
| The chef — who reads and executes the recipe | ||
| The final dish — what comes out at the end |
The Language Spectrum
Programming languages exist on a spectrum, from the computer's native tongue to languages that resemble human speech.
Low-Level
Closer to Hardware ⚙️
Less abstraction
Faster, but harder to use
High-Level
Closer to Human 🧑💻
More abstraction
Slower, but easier to use
Activity: Sort the Languages
Click each item to place it in the correct category. Is it Low-Level or High-Level?
🔍 Low-Level Languages
These languages provide little to no abstraction from a computer's hardware and are very close to machine code.
Machine Language
- The "native" language of the CPU.
- Consists of binary code (0s and 1s).
- Not human-readable.
01001000 01100101 01101100 01101100 01101111
(This is "Hello" in binary)
🔍 Low-Level Languages (cont.)
Assembly Language
- A step above machine code.
- Uses mnemonics (short words) like
MOV,ADD. - Requires an assembler to convert to machine code.
MOV AL, 61h
(Move the value 61 (hex) into register AL)
Margaret Hamilton, 1969: the Apollo code, printed out
Activity: Binary Letter Explorer
Every character stored by a computer is encoded as 8-bit binary. Click a letter to see its binary representation.
🚀 High-Level Languages
Designed to be easy for humans to read, write, and maintain, with strong abstraction from hardware details.
Characteristics
- English-like syntax
- Easier to learn and debug
- Portable across different computer systems
- Focus on logic, not hardware management
Popular Examples
- 🐍 Python
- ☕ Java
- 🌐 JavaScript
- #️⃣ C#
- ++ C++
FORTRAN, one card per line of code
The Translation Problem
Computers only understand machine code, but we write in high-level languages. How do we bridge this gap?
High-Level Code ➡️ ❓ ➡️ ⚙️
Machine Code
High-level source code must be translated into low-level machine code before the CPU can execute it.
Compilers vs. Interpreters 📊
The translation is handled by two types of programs: Compilers and Interpreters.
Compiler
- Translates the entire program at once.
- Creates a separate executable file (e.g.,
.exe). - Execution is generally faster.
- Errors are reported after the whole program is checked.
- Examples: C, C++, Java
Interpreter
- Translates the program line by line.
- No separate executable file is created.
- Execution is generally slower.
- Errors are reported as soon as they are found.
- Examples: Python, JavaScript, Ruby
How a Compiler Works ⚙️
Source Code
my_program.cpp
Compiler
Translates all at once
Executable File
my_program.exe
Key Idea: Compile once, run anytime. The translation and execution are two separate steps.
Grace Hopper, compiler pioneer
How an Interpreter Works ⚡
Source Code
my_script.py
Interpreter
Translates & Executes
Line by Line
Immediate Output
Program runs directly
Key Idea: Translation and execution happen at the same time, every time you run the script.
🎬 Interpreter vs Compiler
Application in Nepal 🇳🇵
The choice of language impacts many local tech solutions.
Which language for which job?
- Building a Digital Wallet (e.g., eSewa, Khalti): Performance and security are critical. Compiled languages like Java or Kotlin (for Android) are a strong choice.
- Developing a News Portal (e.g., OnlineKhabar): Rapid updates and content management are key. Interpreted languages like PHP or JavaScript (with frameworks) allow for fast development cycles.
- Data Analysis for Trekking Tourism: Scripting and quick analysis are needed. Python is ideal due to its powerful data science libraries and ease of use.
Key Takeaways
- Programming languages are the tools we use to give instructions to computers, ranging from low-level to high-level.
- Low-level languages (Machine, Assembly) are close to the hardware, offering speed but complexity.
- High-level languages (Python, Java) are close to human language, offering simplicity and portability.
- Compilers translate an entire program at once into an executable file.
- Interpreters translate and execute a program line by line, at the same time.
Image & Video Credits
Images
- "Margaret Hamilton - restoration" (1969): Draper Laboratory, restored by Adam Cuerden, Public domain — https://commons.wikimedia.org/wiki/File:Margaret_Hamilton_-_restoration.jpg
- "Fortran punch card ESA": Till Niermann, CC BY-SA 3.0 — https://commons.wikimedia.org/wiki/File:Fortran_punch_card_ESA.jpg
- "Commodore Grace M. Hopper, USN (covered)" (1984): James S. Davis, US Navy, Public domain — https://commons.wikimedia.org/wiki/File:Commodore_Grace_M._Hopper,_USN_(covered).jpg
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Videos (YouTube)
- LearnFree (GCFGlobal), "Open Source vs. Closed Source Software" (0:19 to 1:31)
- TVOntario, Bits and Bytes, "Interpreters and Compilers (Bits and Bytes, Episode 6)" (1:16 to 3:00)
Exam Practice 📝
Short answer
- What is COTS software? Give two examples.
- What is a programming language? Differentiate between syntax and logic errors.
- Differentiate between open-source software and freeware.
- What is assembly language? What is an assembler?
Long answer
- Explain the different methods of acquiring software with their advantages and disadvantages.
- Compare low-level and high-level languages with examples.
Revise the answers in the full notes linked on the last slide.
Thank You
Questions before we wrap this hour?
Next: Unit 4 · Session 3 — Operating Systems
📖 Read the full notes: How Software is Acquired: Build vs. Buy · An Introduction to Programming Languages