---
title: "Case study: problems after implementation"
subject: "Instrumentation II"
chapter: 10
key: "semester_5/instrumentation_ii:cs-problems-after-implementing"
source: https://www.bctengineer.com/q/semester_5/instrumentation_ii/cs-problems-after-implementing
site: BCT Engineering
---

# Case study: problems after implementation

Instrumentation II · Chapter 10: Case Study

- Asked in: 2075 Asoj
- Answer checked by Claude Sonnet 5.5 on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/instrumentation_ii/cs-problems-after-implementing
- Whole chapter: https://www.bctengineer.com/md/semester_5/instrumentation_ii/chapter-10

## Question

Mention different types of problems that might occur after implementing the [system] [question text is cut off in the scan].

## Short answer

After implementation, technical issues like EMI, sensor drift, software hangs, and communication faults can occur, along with operator resistance and spares dependency. Mitigations include shielding, UPS, watchdog, pilot run, training, manual override, and preventive maintenance.

## Answer

The question text is cut off in the scan; it is read as: problems that might occur after implementing the proposed (automatic control) system in the case-study plant.

#### Technical problems
1. **Electrical noise and EMI** from motors, relays and VFDs corrupt sensor signals and cause false triggering (need shielding, grounding, filters).
2. **Ground loops and power-quality problems:** voltage dips, surges and power cuts reset the controller (use UPS, surge protection).
3. **Sensor drift and failure,** needing periodic calibration; wiring faults.
4. **Software bugs** and controller hang-ups (watchdog needed); loss of settings.
5. **Communication errors** on the network (RS-485 faults, wrong baud rate or addresses).
6. **Single point of failure** if there is no redundancy or manual bypass.
7. **Compatibility** problems with old equipment.

#### Organisational problems
- Operator resistance and lack of skills; training needed.
- Dependence on a few experts or on the supplier for spares and support.
- Higher maintenance cost and spare-part availability.
- Data and cyber security, and production stoppage during commissioning.

#### Remedies
Pilot run, parallel operation with the old system, training, preventive maintenance, spares stock, manual override, documentation and a support contract.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Motors, relays and VFDs cause false triggering and corrupted sensor signals. What fixes this?
   A. Shielding, grounding and filters
   B. Calibration only
   C. More operators
   D. A faster baud rate
   Answer: A. EMI is reduced by shielding, proper grounding and filtering. (Key point: Electrical noise)

2. What protects against software bugs and controller hang-ups?
   A. A larger LCD
   B. A watchdog timer
   C. A longer cable
   D. A higher baud rate
   Answer: B. A watchdog resets the controller when the firmware stops responding. (Key point: Watchdog for software hang-ups)

3. Which remedy reduces the risk of a single point of failure and commissioning problems?
   A. Removing the old system immediately
   B. Skipping training
   C. Parallel operation with the old system and a manual override
   D. Using one unsupported spare
   Answer: C. Parallel operation and manual override keep production going if the new controller fails. (Key point: Single point of failure remedies)

## Related in Instrumentation II

- [Case study: new system vs existing (cost, manpower)](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Acs-cost-manpower-automation) — Instrumentation II, chapter 10, asked 4×
- [Case study: recommended changes and convincing](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Acs-recommend-changes) — Instrumentation II, chapter 10, asked 2×
- [Case study: current control and recommendation](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Acs-existing-recommend-problems) — Instrumentation II, chapter 10, asked 3×
- [Case study: revamping MBI system for CEO](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Acs-ceo-revamp) — Instrumentation II, chapter 10
- [Case study: existing vs proposed system](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Acs-2074asoj) — Instrumentation II, chapter 10
- [Case study: feasibility, drawbacks, convincing](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Acs-2072kartik-feasibility) — Instrumentation II, chapter 10

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