diff --git a/Sources/AOC2018/data/day07.txt b/Sources/AOC2018/data/day07.txt
new file mode 100644
index 0000000..609cd83
--- /dev/null
+++ b/Sources/AOC2018/data/day07.txt
@@ -0,0 +1,101 @@
+Step G must be finished before step X can begin.
+Step X must be finished before step B can begin.
+Step A must be finished before step I can begin.
+Step D must be finished before step H can begin.
+Step O must be finished before step T can begin.
+Step H must be finished before step C can begin.
+Step S must be finished before step E can begin.
+Step U must be finished before step M can begin.
+Step M must be finished before step Z can begin.
+Step R must be finished before step N can begin.
+Step C must be finished before step Q can begin.
+Step T must be finished before step P can begin.
+Step I must be finished before step W can begin.
+Step W must be finished before step N can begin.
+Step P must be finished before step J can begin.
+Step N must be finished before step F can begin.
+Step Y must be finished before step J can begin.
+Step J must be finished before step L can begin.
+Step L must be finished before step E can begin.
+Step E must be finished before step B can begin.
+Step Q must be finished before step B can begin.
+Step F must be finished before step K can begin.
+Step V must be finished before step K can begin.
+Step Z must be finished before step B can begin.
+Step B must be finished before step K can begin.
+Step G must be finished before step U can begin.
+Step E must be finished before step V can begin.
+Step A must be finished before step Z can begin.
+Step C must be finished before step V can begin.
+Step R must be finished before step B can begin.
+Step Q must be finished before step Z can begin.
+Step R must be finished before step K can begin.
+Step T must be finished before step B can begin.
+Step L must be finished before step B can begin.
+Step M must be finished before step K can begin.
+Step T must be finished before step Z can begin.
+Step W must be finished before step B can begin.
+Step I must be finished before step E can begin.
+Step A must be finished before step M can begin.
+Step V must be finished before step Z can begin.
+Step Y must be finished before step B can begin.
+Step Q must be finished before step F can begin.
+Step W must be finished before step Y can begin.
+Step U must be finished before step K can begin.
+Step D must be finished before step F can begin.
+Step P must be finished before step F can begin.
+Step N must be finished before step L can begin.
+Step H must be finished before step T can begin.
+Step H must be finished before step L can begin.
+Step C must be finished before step T can begin.
+Step H must be finished before step I can begin.
+Step Z must be finished before step K can begin.
+Step L must be finished before step Z can begin.
+Step Y must be finished before step K can begin.
+Step I must be finished before step V can begin.
+Step P must be finished before step K can begin.
+Step P must be finished before step N can begin.
+Step G must be finished before step D can begin.
+Step I must be finished before step J can begin.
+Step H must be finished before step K can begin.
+Step L must be finished before step Q can begin.
+Step D must be finished before step M can begin.
+Step O must be finished before step V can begin.
+Step R must be finished before step L can begin.
+Step D must be finished before step W can begin.
+Step M must be finished before step J can begin.
+Step O must be finished before step R can begin.
+Step N must be finished before step Z can begin.
+Step Y must be finished before step V can begin.
+Step W must be finished before step L can begin.
+Step U must be finished before step Y can begin.
+Step S must be finished before step V can begin.
+Step M must be finished before step P can begin.
+Step X must be finished before step A can begin.
+Step A must be finished before step E can begin.
+Step A must be finished before step L can begin.
+Step A must be finished before step R can begin.
+Step V must be finished before step B can begin.
+Step P must be finished before step B can begin.
+Step E must be finished before step F can begin.
+Step T must be finished before step V can begin.
+Step S must be finished before step R can begin.
+Step T must be finished before step F can begin.
+Step P must be finished before step Y can begin.
+Step A must be finished before step C can begin.
+Step J must be finished before step F can begin.
+Step H must be finished before step B can begin.
+Step C must be finished before step E can begin.
+Step P must be finished before step E can begin.
+Step D must be finished before step I can begin.
+Step X must be finished before step F can begin.
+Step T must be finished before step Q can begin.
+Step J must be finished before step B can begin.
+Step C must be finished before step B can begin.
+Step P must be finished before step Q can begin.
+Step H must be finished before step R can begin.
+Step F must be finished before step B can begin.
+Step T must be finished before step J can begin.
+Step A must be finished before step W can begin.
+Step N must be finished before step K can begin.
+Step T must be finished before step E can begin.
diff --git a/Sources/AOC2018/day07.swift b/Sources/AOC2018/day07.swift
new file mode 100644
index 0000000..78f438a
--- /dev/null
+++ b/Sources/AOC2018/day07.swift
@@ -0,0 +1,125 @@
+//
+// Advent of Code 2018 "Day 7: The Sum of Its Parts"
+//
+
+import Foundation
+
+struct Instruction: Equatable, Comparable {
+    var complete = Character(" ")
+    var before = Character(" ")
+
+    static func == (lhs: Instruction, rhs: Instruction) -> Bool {
+        return (lhs.complete == rhs.complete) && (lhs.before == rhs.before)
+    }
+
+    static func < (lhs: Instruction, rhs: Instruction) -> Bool {
+        return lhs.complete < rhs.complete
+    }
+}
+
+class SumParts {
+    var instrList: [Instruction] = []
+    var inventoryComplete: [Character] = []
+
+    // Supply filename for input ex: '/home/peterr/AOC2018/Sources/AOC2018/data/day07.txt'
+    init(withFile filename: String) {
+        let instrString = Tools.readFile(fromPath: filename)
+        var instrArray = instrString.components(separatedBy: "\n")
+        // This gurd statement is just an excuse to use guard
+        // I'm assuming the last string is an empty string, if not DON'T remove the last string
+        guard let lastStr = instrArray.last, lastStr.count == 0 else { return }
+        instrArray.removeLast()  // empty string
+        parseData(withInstructions: instrArray)
+    }
+
+    // Supply test data in the form of a String
+    init(withString instrString: String) {
+        let instrArray = instrString.components(separatedBy: "\n")
+        parseData(withInstructions: instrArray)
+    }
+
+    func parseData(withInstructions instr: [String]) {
+        for ins in instr {
+            instrList.append(Instruction(complete: ins[5], before: ins[36]))
+        }
+    }
+
+    func getNextAvailable() -> Character? {
+        var availDict: [Character : Bool] = [:]
+        for index in 0..<instrList.count {
+            if !instrList.contains(where: { $0.before == instrList[index].complete} ) {
+                availDict[instrList[index].complete] = true
+            }
+        }
+        var available = Array(availDict.keys)
+        available.sort()
+        return available.first
+    }
+
+    func completeInstructions() -> String {
+        var retVal = ""
+        var last: Character = "*"
+        while let instruction = getNextAvailable() {
+            retVal.append(instruction)
+            if let lastInstr = instrList.first(where: { $0.complete == instruction }) {
+                last = lastInstr.before
+            }
+            instrList.removeAll(where: { $0.complete == instruction })
+        }
+        retVal.append(last)
+        return retVal
+    }
+}
+
+class Day07: AOCDay {
+    lazy var tests: (() -> ()) = day07Tests
+    lazy var final: (() -> ()) = day07Final
+
+    let testData = """
+        Step C must be finished before step A can begin.
+        Step C must be finished before step F can begin.
+        Step A must be finished before step B can begin.
+        Step A must be finished before step D can begin.
+        Step B must be finished before step E can begin.
+        Step D must be finished before step E can begin.
+        Step F must be finished before step E can begin.
+        """
+
+    func testSumPartsInit() {
+        var instr = SumParts(withString: testData)
+        XCTAssertEqual(test: "testSumPartsInit string 0", withExpression: (instr.instrList[0].before == "A"))
+        XCTAssertEqual(test: "testSumPartsInit string 4", withExpression: (instr.instrList[4].complete == "B"))
+        instr = SumParts(withFile: "/home/peterr/AOC2018/Sources/AOC2018/data/day07.txt")
+        XCTAssertEqual(test: "testSumPartsInit file 0", withExpression: (instr.instrList[0].before == "X"))
+        XCTAssertEqual(test: "testSumPartsInit file 4", withExpression: (instr.instrList[4].complete == "O"))
+    }
+
+    func testGetNextAvailable() {
+        let instr = SumParts(withString: testData)
+        if let avail = instr.getNextAvailable() {
+            XCTAssertEqual(test: "testGetNextAvailable", withExpression: (avail == "C"))
+        } else {
+            XCTAssertEqual(test: "testGetNextAvailable", withExpression: (false))
+        }
+    }
+
+    func testCompleteInstructions() {
+        let instr = SumParts(withString: testData)
+        let answer = instr.completeInstructions()
+        XCTAssertEqual(test: "testCompleteInstructions", withExpression: (answer == "CABDFE"))
+    }
+
+    func day07Tests() {
+        testSumPartsInit()
+        testGetNextAvailable()
+        testCompleteInstructions()
+    }
+
+    func day07Final() {
+        let retVal = "None"
+        let instr = SumParts(withFile: "/home/peterr/AOC2018/Sources/AOC2018/data/day07.txt")
+        let answer = instr.completeInstructions()
+        print("Answer to part 1 is: \(answer)")
+        print("Answer to part 2 is: \(retVal)")
+    }
+}
diff --git a/Sources/AOC2018/main.swift b/Sources/AOC2018/main.swift
index fba28c2..a037f89 100644
--- a/Sources/AOC2018/main.swift
+++ b/Sources/AOC2018/main.swift
@@ -5,7 +5,7 @@
 import Foundation
 
 let showTests = true
-let onlyOneDay = 0
+let onlyOneDay = 7
 var allTests: [(() -> ())] = []
 var allFinal: [(() -> ())] = []
 
@@ -18,6 +18,7 @@ allTests.append(Day03().tests)
 allTests.append(Day04().tests)
 allTests.append(Day05().tests)
 allTests.append(Day06().tests)
+allTests.append(Day07().tests)
 
 // Compile list of Answers
 allFinal.append(Day01().final)
@@ -26,6 +27,7 @@ allFinal.append(Day03().final)
 allFinal.append(Day04().final)
 allFinal.append(Day05().final)
 allFinal.append(Day06().final)
+allFinal.append(Day07().final)
 
 if onlyOneDay > 0 {
     print("\nDay \(onlyOneDay)")