Realization Technologies
- Providers of enterprise software to support multi-project Critical Chain implementations.
- http://www.realization.com/

Goldratt's Marketing Ltd.
- Includes information about TOC consultants, books and other training materials for sale, a list of upcoming events, and a history of the Theory of Constraints.
- http://TOC-Goldratt.com/

Vector Strategies
- Theory of Constraints based solutions provider. TOC solutions available include: critical chain, drum buffer rope, thinking processes, throughput accounting, strategic planning, sales, marketing, distribution and replenishment.
- http://www.vectorstrategies.com/

Synchrono
- Provides supply chain planning software based on Theory of Constraints and lean manufacturing principles.
- http://www.synchrono.com/

Avraham Y. Goldratt Institute
- Utilizes theory of constraints (TOC) to provide business solutions in the areas of business operations, business policy and strategy, project management, accounting and finance, as well as sales and marketing.
- http://www.goldratt.com

R.B. Vollum & Associates
- Consulting and education services covering the Theory of Constraints, continuous manufacturing improvement and synchronous flow management.
- http://www.rbvollum.com/

Constraints Management Group
- Strives to create holistic solutions that maximize a system's performance by identifying, exploiting and synchronizing around critical leverage points.
- http://www.thoughtwarepeople.com/

Goal Systems International
- Disseminates and applies the principles and tools of constraint management to improve organizational systems.
- http://www.goalsys.com/

Focused Performance
- Offers constraint based consulting services and presentations. Site contains articles, information and upcoming events related to the Theory of Constraints.
- http://www.focusedperformance.com/

The TOC Center Inc.
- Global consulting company; the site contains information on theory of constraints including application of TOC, case studies, seminars, and suggested reading.
- http://www.tocc.com/

Goldratt-TOC
- Provides Theory of Constraints related consulting services covering engineering, sales and marketing, strategy, finance and operations.
- http://www.toc.co.uk/

Chesapeak Consulting Inc.
- Applies business tools including Six Sigma, and Theory of Constraints methodologies to project management, synchronous flow manufacturing, sales, marketing, modeling and simulation.
- http://www.chesapeak.com/