Insulin Lispro 6 Days Versus Insulin Aspart 6 Days in Pump Use

Inclusion Criteria: * Diagnosed with type 1 diabetes (World Health Organization criteria) for at least 24 months. * Treated with continuous subcutaneous insulin infusion therapy for the previous 6 months. * Mean total daily insulin dose for 3 days prior to screening equal to or less than 46 units/day using a 300-unit reservoir or less than or equal to 26 units/day using a 180 unit reservoir. * Baseline body mass index (BMI) less than or equal to 35.0 kg/m\^2. * Baseline glycosylated hemoglobin (HbA1c) 5% to 9%. Exclusion Criteria: * Impaired renal function (serum creatinine greater than or equal to 2.0 milligrams per deciliter \[mg/dL\]). * Legal blindness. * Have had any episode of hypoglycemic coma, seizures, or disorientation in the 12 months prior to screening. * Have had hypoglycemia unawareness (routinely asymptomatic at blood glucose (BG) less than 45 mg/dL) in the 12 months prior to screening. * Have had any emergency room visits or hospitalizations due to poor glucose control in the 12 months prior to screening. * Have had a pump-related infusion site abscess in the 12 months prior to screening. * Have had multiple, clinically significant occlusions as judged by the investigator. * Have had any infection with staphylococcus aureus in the past 5 years. * Have one of the following concomitant diseases: presence of clinically significant hematologic, oncologic, renal, cardiac, hepatic, or gastrointestinal disease, or any other serious disease considered by the investigator to be exclusionary. * Patients with malignancy other than basal cell or squamous cell skin cancer who have not yet been treated, are currently being treated, or who were diagnosed less than 5 years ago. * Have had a blood transfusion or severe blood loss within 3 months prior to screening, or have known hemoglobinopathy, hemolytic anemia or sickle cell anemia, or any other traits of hemoglobin abnormalities known to interfere with HbA1c methodology. * Are receiving chronic (lasting longer than 14 consecutive days) systemic glucocorticoid therapy (excluding topical, intra-articular, intraocular and inhaled prescriptions), or have received such therapy within the 4 weeks immediately preceding screening. * Have an irregular sleep/wake cycle (for example, patients who sleep during the day and work during the night), in the investigator's opinion. * Have known hypersensitivity or allergy to any of the study insulins or their excipients. * Are breastfeeding or pregnant, or intend to become pregnant during the course of the study, or are sexually active women of childbearing potential not actively practicing birth control by a method determined by the investigator to be medically acceptable. * Are currently enrolled in, or discontinued within the last 30 days from, a clinical trial involving an off-label use of an investigational drug or device (other than the study drug/device used in this study), or concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study. * Have previously completed or withdrawn from this study after having signed the informed consent document (ICD). * Are unwilling or unable to comply with the use of a data collection device to directly record data from the patient.