Handout

Prompt Techniques

Practical Guide for Technical Tasks

About this guide

This guide provides a comprehensive overview of proven prompt engineering techniques specifically for the food packaging industry. Based on the systematic survey by Schulhoff et al. (2024), 58 text-based prompting techniques are presented in 6 main categories, with focused application examples for coffee, nut, and snack packaging.

Table of Contents

  1. Fundamentals of Prompt Engineering
  2. Basic Techniques with Food Packaging Examples
  3. Advanced Techniques for Complex Tasks
  4. Specialized Applications for Food Engineering
  5. Additional Expert Roles for Food Packaging
  6. References

1. Fundamentals of Prompt Engineering

What is Prompt Engineering?

Prompt engineering is the iterative process of developing a prompt through modification or alteration of the prompting technique used. It enables so-called Large Language Models (LLMs - such as ChatGPT, Gemini, Claude) to learn specific tasks without weight modifications.

GPT stands for 'Generative Pre-trained Transformer' - a family of AI language models that includes well-known applications such as ChatGPT, Claude, or Gemini.

Prompt engineering is the key to unlocking the full potential of GPTs. It involves designing the input instructions (prompts) so that the model delivers exactly the desired responses. This follows an iterative process: experiment, adjust, improve.

Define the goal clearly

First consider what result you expect:

Example
"Explain to me how photosynthesis works - in a way that a 10-year-old would understand."

Provide context

The more relevant information the GPT receives, the more appropriate the responses will be. Instead of a vague question like:

"Write a report"

better:

"Write a factual report about climate change in Europe in 2025. Length: approx. 300 words. Target audience: political science students."

Specify format and style

You can specify exactly how the response should be structured:

Example
"Create a list of five marketing strategies for a pharma start-up. Briefly describe each strategy (max. 50 words)."

Refine step by step

After the initial response, consider:

Then adjust the prompt and ask again.

Example
"Add a concrete example from the pharma industry to each marketing strategy."

Main categories of prompt techniques

In-Context Learning (ICL)

Models learn from examples directly within the prompt

Thought Generation

Encouraging the model to articulate its reasoning process

Decomposition

Breaking down complex tasks into subtasks

Ensembling

Combining different prompts or models

Self-Criticism

Self-evaluation and self-correction of responses

Role Prompting

Assigning specific expert roles

2. Basic Techniques with Food Packaging Examples

Zero-Shot Prompting ~65% Success Rate

Direct task instruction without examples.

Example – Coffee Quality Control
Analyze the following packaging parameters for coffee beans and evaluate the barrier properties: material thickness 80μm, oxygen permeability 0.5 cc/m²/day, water vapor permeability 2.0 g/m²/day.
Example – HACCP Nut Packaging
Create a risk analysis for the packaging of roasted almonds regarding allergen cross-contamination in a multi-product facility.

Few-Shot Prompting ~69% Success Rate

Learning through a few examples in the prompt.

Example – Snack Packaging Quality Assessment
Evaluate the packaging quality according to the following schema:

Example 1: Chips, 50g, polypropylene bag, nitrogen flush → Rating: Good (adequate barrier)
Example 2: Nuts, 200g, aluminum composite, vacuum → Rating: Excellent (optimal shelf life)

Now evaluate: Popcorn, 80g, PET film, normal atmosphere

Role Prompting ~75% Success Rate

Assigning a specific expert role for better results.

Example – Food Technologist for Coffee
You are an experienced food technologist specializing in coffee packaging with 15 years of experience in quality control and aroma protection technologies. You have led over 200 successful packaging projects and are an expert in barrier films and gas exchange optimization. Analyze the optimal packaging solution for single-origin Arabica beans with a 14-day shelf life after roasting.
Example – HACCP Expert for Nuts
You are a HACCP expert with international certification and over 10 years of experience in successful audits in the nut industry. You specialize in critical control points for nut packaging and have successfully guided 150+ facilities through FDA and BRC audits. Create a detailed CCP plan for a new hazelnut packaging line with automatic metal detection and allergen management.

Chain-of-Thought (CoT) Prompting ~69% Success Rate

Step-by-step reasoning process for complex problems.

Example – Shelf Life Calculation
Calculate the expected shelf life of vacuum-packed roasted coffee beans. Think step by step:
  1. Analyze the residual oxygen levels after vacuum sealing
  2. Consider the CO2 degassing of the beans
  3. Evaluate the barrier properties of the packaging
  4. Calculate the aroma loss over time
  5. Determine the acceptable quality threshold
  6. Calculate the final shelf life duration

3. Advanced Techniques for Complex Tasks

Decomposition - Least-to-Most Prompting

Breaking down complex problems into smaller, solvable sub-problems.

Example – Packaging Line Optimization
Optimize the production efficiency of a snack packaging line:
  1. What individual processes exist in snack packaging?
  2. Where are the most frequent downtimes?
  3. Which machine parameters affect cycle time?
  4. How can changeover times be minimized?
  5. How can Overall Equipment Effectiveness (OEE) be increased by 15%?

Self-Consistency Ensembling ~63% Success Rate

Generate multiple solution paths and select the most consistent one.

Example – Packaging Material Selection
Evaluate 3 different approaches for optimal packaging material selection for 6-month shelf life of nut mixes:

Approach 1: Focus on oxygen barrier
Approach 2: Focus on water vapor barrier
Approach 3: Focus on aroma protection

Conduct a complete analysis for each approach and select the most consistent solution.

Self-Refine (Self-Criticism)

Self-evaluation and iterative improvement of responses.

Example – URS Document Quality Review
Create a User Requirements Specification (URS) document for a new coffee packaging machine. Then review your document for:
  1. Completeness of all requirements
  2. Measurability of specifications
  3. Compliance with FDA/EU regulations
  4. Technical feasibility
  5. Budget compatibility
Revise the document based on your review.

4. Specialized Applications for Food Engineering

PMI PMP Project Management

Example Prompt – Risk Management Plan

You are an experienced PMI PMP-certified project manager with 15+ years of experience in food packaging projects. You have led over 60 successful implementations with an average 98% on-time delivery rate. Create a detailed risk management plan according to PMI standards for a CHF 2.5 million project to implement a fully automated organic snack packaging line with the following risk categories: Technical Risks, Supplier Risks, Regulatory Risks, Market Risks. Use a risk matrix with Probability vs. Impact and define concrete mitigation strategies.

Example Prompt – Stakeholder Management

You are a senior project manager specializing in food industry projects with PMP certification. You have successfully led 45+ complex packaging projects. Develop a comprehensive stakeholder analysis and communication strategy for the introduction of a new nut packaging line. Consider internal stakeholders (production, QA, maintenance, management) and external (suppliers, auditors, customers). Define communication frequency, channels, and escalation paths according to PMI best practices.

URS Document Creation

Example Prompt – Technical Specifications

You are an experienced packaging engineer with 12 years of experience in specifying packaging machines for the food industry. You have created over 100 URS documents that were accepted by suppliers 95% of the time without major revisions. Create a detailed URS document for a horizontal form-fill-seal machine for coffee pods. Specify: performance requirements (200 pods/min), packaging materials (aluminum composite), quality requirements (seal strength >2N/15mm), automation level (fully automated with PLC), HMI requirements, validation requirements per FDA 21 CFR Part 111.

HACCP Implementation

Example Prompt – Nut Allergen Hazard Analysis

You are a HACCP expert with 18 years of experience and Certified HACCP Auditor certification. You have conducted over 200 successful HACCP implementations in the nut industry with a 100% audit success rate for FDA, BRC, and IFS. Conduct a comprehensive hazard analysis for a new almond packaging line that also processes other nuts. Consider: Biological hazards (Salmonella, mold), Chemical hazards (allergen cross-contamination, cleaning agent residues), Physical hazards (metal fragments, packaging material fragments). Define for each identified hazard the critical control points (CCPs), critical limits, monitoring procedures, and corrective actions.

Machine Maintenance and Predictive Maintenance

Example Prompt – Maintenance Plan Optimization

You are a maintenance engineer with 20 years of experience in food packaging equipment and Certified Maintenance & Reliability Professional (CMRP). You have reduced maintenance costs by an average of 35% across over 50 facilities and increased equipment availability to >95%. Develop an optimized maintenance plan for a high-speed snack packaging line (600 bags/min) with the following components: forming shoulders, sealing bars, longitudinal cutters, cross cutters, product infeed. Define preventive maintenance intervals based on operating hours, critical wear parts, condition monitoring parameters, and CMMS integration. Consider production schedules and minimize downtime.

Process Optimization and Efficiency Improvement

Example Prompt – OEE Analysis and Improvement

You are a Lean Six Sigma Black Belt specializing in food manufacturing with 14 years of experience in process optimization. You have increased Overall Equipment Effectiveness (OEE) by an average of 22% across over 80 projects. Analyze a coffee capsule packaging line with a current OEE of 68% and develop an improvement plan to >85%. Analyze: Availability (planned vs. unplanned downtime), Performance (actual vs. target speed), Quality (scrap and rework rate). Use root cause analysis for the top 3 loss sources and define concrete improvement measures with cost-benefit analysis.

5. Additional Expert Roles for Food Packaging

Example Prompt – Regulatory Affairs Specialist

You are a Regulatory Affairs Manager with 16 years of experience in the food packaging industry and Certified Regulatory Affairs Professional (RAC). You have conducted over 300 successful submissions to FDA, EFSA, and Health Canada with a 94% first-time approval rate. You are an expert in food contact materials, migration testing, and novel food regulations. Assess the regulatory requirements for a new bio-based packaging film for organic nuts for the EU and US markets.

Example Prompt – Sustainability Manager

You are a Sustainability Manager with 12 years of experience in sustainable packaging and Certified Packaging Professional (CPP). You have supported over 40 companies in reducing their packaging footprint by an average of 30%. You are an expert in life cycle assessment, circular economy principles, and sustainable packaging certifications. Develop a comprehensive sustainability strategy for snack packaging with targets for 2030: 50% material reduction, 100% recyclable materials, carbon-neutral packaging.

Example Prompt – Packaging Engineer for Barrier Technologies

You are a Senior Packaging Engineer with a PhD in Materials Science and 18 years of experience in high-barrier packaging. You have developed over 25 patents in the area of multi-layer films and barrier coatings. You are an expert in oxygen/water vapor permeation, aroma migration, and active packaging systems. Develop an innovative packaging solution for premium coffee with a 24-month shelf life at room temperature without quality loss.

Example Prompt – Quality Controller for Snack Production

You are a QC Manager with 14 years of experience in the snack industry and Certified Quality Engineer (CQE). You have implemented quality systems according to BRC, SQF, and FSSC 22000 with 100% successful re-audits. You are an expert in statistical process control, sensory testing, and accelerated shelf life testing. Develop a comprehensive QC protocol for a new popcorn product line with automatic quality checks every 15 minutes.

6. References

Primary Source

Schulhoff, S., Ilie, M., Balepur, N., et al. (2024). The Prompt Report: A Systematic Survey of Prompt Engineering Techniques. University of Maryland, Learn Prompting.

Supplementary Sources

Schlatter, R. (2025). Introduction to AI for Swiss SMEs. Moro Vision GmbH.
Schlatter, R. (2025). AI Methods and Technology - Module 1. Moro Vision GmbH.

Further Reading

Brown, T., et al. (2020). Language Models are Few-Shot Learners. NeurIPS.
Wei, J., et al. (2022). Chain-of-Thought Prompting Elicits Reasoning in Large Language Models. NeurIPS.
PMI (2021). A Guide to the Project Management Body of Knowledge (PMBOK Guide) – Seventh Edition.
Codex Alimentarius Commission. HACCP Guidelines (CAC/RCP 1-1969).