diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..8ed01f1
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module git.ecogood.org/andras.schroepfer/goodcalc
+
+go 1.15
diff --git a/goodcalc.go b/goodcalc.go
new file mode 100644
index 0000000..1fff7d2
--- /dev/null
+++ b/goodcalc.go
@@ -0,0 +1,42 @@
+// Package goodcalc is a good balance calculator
+package goodcalc
+
+type Matrix struct {
+	MaxPoints    int
+	Stakeholders []Stakeholder
+}
+
+type Stakeholder struct {
+	No     string
+	Weight float32
+}
+
+type Theme struct {
+	No              string
+	Weight          float32
+	Aspects         []Aspect
+	NegativeAspects []NegativeAspect
+	ThemeCalc       // calculatet values
+}
+
+type Aspect struct {
+	No     string
+	Weight float32
+	Points int
+}
+
+type NegativeAspect struct {
+	Aspect
+}
+
+type ThemeCalc struct {
+	CalcWeight              float32
+	WeightFactor            float32
+	MaxPoints               float32
+	NrPositiveAspects       int
+	ValuationPoints         int
+	EstPercentage           float32
+	blancePoints            int
+	NegativeValuationPoints int
+	NegativeBlancePoints    int
+}