[jachguate]

Podes tratar polimórficamente a las series partiendo de su clase base: TChartSeries

Acabo de hacer esto, que funcionó perfectamente:

Código Delphi [-]
function TForm1.CreaSerie(Clase: TChartSeriesClass): TChartSeries;
begin
  Result := Clase.Create(Chart1);
  Chart1.AddSeries(Result);
  Result.Add(random(50));
  Result.Add(random(50));
  Result.Add(random(50));
  Result.Add(random(50));
  Result.Add(random(50));
  Result.Add(random(50));
  Result.Add(random(50));
  Result.Add(random(50));
  Result.Add(random(50));
  Result.Add(random(50));
  Result.Add(random(50));
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  CreaSerie(TBarSeries);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  CreaSerie(TLineSeries);
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  CreaSerie(THorizBarSeries);
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
  CreaSerie(THorizLineSeries);
end;

procedure TForm1.Button5Click(Sender: TObject);
begin
  CreaSerie(TAreaSeries);
end;

Hasta luego.