Thirty new PCs and one broken screen
A school fits thirty new PCs over a weekend. On Monday, one room cannot log in. Nobody knows why.
Was it the PC, the program, the student list, the cable link, or the whole service? Testing each part on its own would have shown it.
By the end of this lesson
Note
I can explain why each part of a solution is tested before the parts are joined.
Key words
| Word | What it means |
|---|---|
| Component | one part of a solution |
| Hardware | the physical parts you can touch |
| Software | the programs that run on hardware |
| Interface | the point where two parts meet and pass data |
| Service | what the user finally gets from the whole solution |
| Fault | something that is not working as it should |
The cells students fill in are left blank in this preview.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Three reasons to test early
First, a fault is cheaper to fix early. A bad memory stick is a two minute swap before the PC is in a classroom, and a day of lost lessons after.
Second, you know where the fault is. If each part passed alone, the fault is in how they join.
Third, you gain confidence. You can say what you tested and what happened.
Five things to test on their own
| What | A test on its own | What it finds |
|---|---|---|
| Software | Install the program on one PC and open it | Install errors, missing files |
| Hardware | Run a memory and disk check on one PC | Faulty parts, loose cables |
| Data | Import ten student records and read them back | Missing or garbled records |
| Interfaces | Join one PC to the printer and print a page | The two parts not talking |
| Resulting service | A student logs in, works and prints | Whether the whole thing does the job |
The cells students fill in are left blank in this preview.
Check
Have a go
Check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.