OpenSearch Visualizations Guide

Overview

OpenSearch Dashboards provides a rich set of visualization tools for analyzing procurement data. While visualizations cannot be permanently saved, they can be shared via URLs and recreated easily using this guide.

Each visualization transforms raw procurement data into meaningful graphical representations. The right visualization can reveal patterns, trends, and insights that might not be apparent from looking at the data tables alone.

This guide will help you select, create, and share visualizations tailored to procurement analysis.

Visualization Types

1. Area Charts

Area charts illustrate trends over time by displaying the evolution of numeric values through filled-in areas. They work particularly well for showing cumulative values or comparing multiple data series.

Use Cases:

• Contract value distribution over time
• Cumulative procurement spending
• Comparative analysis of procurement types

Quick Setup:

1. Select 'Area' visualization
2. X-axis: Date field (e.g., "Dispatch Date")
3. Y-axis: Numeric field (e.g., "Value")
4. Optional: Split series by "Contract Nature"

2. Bar Charts

Bar charts compare categories against numeric values using rectangular bars. The length of each bar represents the value, making it easy to compare magnitudes across different categories.

Use Cases:

• CPV code distribution
• Contract values by country
• Procurement procedures comparison

Quick Setup:

1. Select 'Vertical/Horizontal Bar' visualization
2. X-axis: Category field (e.g., "Country")
3. Y-axis: Count or sum of "Value"
4. Optional: Stack by "Contract Nature"

3. Pie/Donut Charts

Pie and donut charts display proportions of a whole. Each slice represents a category's share of the total, making them ideal for showing percentage distributions.

Use Cases:

• Contract nature distribution
• Procurement route breakdown
• Value range categories

Quick Setup:

1. Select 'Pie' visualization
2. Slice size: Count or sum of "Value"
3. Split slices: Category field (e.g., "Contract Nature")

Procurement Example:
To visualize the distribution of procurement procedures:

1. Create a pie chart with slice size: Count of documents
2. Split slices by "Procurement Type"
3. Use the "Donut" option for better readability
   This reveals which procurement procedures are most commonly used (Open, Restricted, Negotiated, etc.).

4. Data Table

Data tables present detailed information in rows and columns. They enable sorting, pagination, and customized columns, making them ideal for detailed data examination.

Use Cases:

• Contract details listing
• Lot analysis
• Bidder comparison

Quick Setup:

1. Select 'Data Table' visualization
2. Add columns: Select relevant fields
3. Enable sorting and pagination
4. Add sum/average for numeric columns

Procurement Example:
To create a detailed view of high-value contracts:

1. Create a data table with columns: "Title", "Value", "Contracting Authority.Name", "Country", "CPV Description"
2. Add a filter for "Value" > 1,000,000
3. Sort by "Value" in descending order
4. Add sum of "Value" as a footer
   This provides a detailed list of major procurement contracts with essential information.

5. Metric

Metric visualizations display single numbers or values prominently. They're perfect for key performance indicators or summary statistics that need emphasis.

Use Cases:

• Total contract count
• Total value sum
• Average contract value

Quick Setup:

1. Select 'Metric' visualization
2. Choose aggregation (count, sum, average)
3. Optional: Add trend arrow
4. Configure thresholds if needed

6. Heat Maps

Heat maps use color intensity to represent data values in a two-dimensional grid. They're excellent for showing patterns and concentrations across two variables.

Use Cases:

• Geographic distribution of contracts
• Value concentration by region
• Temporal patterns in procurement

Quick Setup:

1. Select 'Heat Map' visualization
2. Y-axis: Category (e.g., "Country")
3. X-axis: Date intervals
4. Color intensity: Count or sum of "Value"

7. Tag Cloud

Tag clouds visualize text data by displaying words with sizes proportional to their frequency. They provide a quick visual impression of dominant terms.

Use Cases:

• Common CPV codes
• Active contracting authorities
• Frequent procurement types

Quick Setup:

1. Select 'Tag Cloud' visualization
2. Size: Count of occurrences
3. Tags: Category field (e.g., "CPV Description")

Procurement Example:
To visualize the most common procurement descriptions:

1. Create a tag cloud with tags: "Title" (using significant terms aggregation)
2. Size: Count of documents
3. Set maximum number of tags to 50
   This highlights the most frequently occurring terms in procurement titles, giving insight into common procurement subjects.

Creating Custom Visualizations

Basic Steps

Creating a visualization in the EU Contract Hub follows this workflow:

1. Click "Visualize" in the left menu
2. Choose "Create visualization"
3. Select visualization type
4. Configure data source
5. Set up visualization parameters

The process is designed to be intuitive, allowing you to see changes in real-time as you configure your visualization.

Data Selection

Before visualizing data, you need to specify what data to include:

1. Choose index pattern (default is the `procure index)
2. Select time range if applicable (e.g., last 5 years)
3. Apply filters as needed (e.g., specific countries or CPV codes)
4. Configure metrics and buckets to define what data to display

Metrics Configuration

Metrics determine the numeric values in your visualization:

• Count: Number of procurement documents (contracts)
• Sum: Total of a numeric field (e.g., contract values)
• Average: Mean value of a numeric field (e.g., average contract value)
• Percentiles: Statistical distribution (e.g., median contract value)
• Unique Count: Number of distinct values (e.g., unique contracting authorities)

Bucket Configuration

Buckets split your data into meaningful groups:

• Date Histogram: Groups by time intervals (e.g., contracts by month)
• Terms: Groups by values of a field (e.g., contracts by country)
• Range: Groups by numeric ranges (e.g., value brackets)
• Filters: Groups by specific criteria (e.g., healthcare vs. non-healthcare)
• Significant Terms: Finds statistically notable terms

Sharing and URL Parameters

Sharing Options

Since visualizations cannot be permanently saved in the EU Contract Hub, sharing is done through URLs:

1. After creating a visualization, click the "Share" button
2. Copy the generated URL (this captures all visualization settings)
3. Share the URL with colleagues (they will see the exact same visualization)
4. Bookmark important visualizations for your own reference

Sharing Tip:
URLs can be quite long, so consider using a URL shortener service for easier sharing. All visualization parameters are encoded in the URL, so shortening doesn't lose any information.

URL Parameters

The shared URL contains parameters that define your visualization:

• Time range selection (from and to dates)
• Applied filters and queries
• Visualization type and configuration
• Metric and bucket settings
• Display options (colors, labels, etc.)

These parameters can be modified directly in the URL if needed, allowing for advanced customization.

Best Practices

Data Presentation

Follow these guidelines for effective data visualization:

1. Choose appropriate visualization type: Use bar charts for comparisons, line/area charts for trends, pie charts for proportions
2. Use clear labels and titles: Make sure viewers understand what they're seeing
3. Apply consistent color schemes: Use colors meaningfully (e.g., same color for same contract type across visualizations)
4. Include relevant context: Add filters to focus on specific segments of data
5. Consider data volume: For large datasets, use aggregations rather than showing all data points

Troubleshooting

To learn about filtering options in visualizations, refer to the Filter System Documentation.