Which type of error would occur if required laboratory work were not ordered for a patient on heparin?

Compliance refers to following guidelines, rules, or recommendations. While ordering laboratory work for a patient on heparin is indeed a part of compliance with best practices in healthcare, the specific error in this scenario relates more to the lack of monitoring the patient's response to the medication rather than a failure of compliance.

Omission generally refers to leaving something out or neglecting to do something. In this case, not ordering the necessary laboratory work for a patient on heparin would indeed be considered an omission, but the critical aspect of this error is the lack of monitoring the patient's condition and response to the medication.

Dispensing involves the distribution of medications to patients. While accurate dispensing is essential for patient safety, the primary concern in this scenario is not related to the dispensing of heparin but rather to the failure to monitor the patient's laboratory values while on this anticoagulant therapy.