CMakeList to compile and link an executable using Boost
As commented by @drescherjm and @NicolasHolthaus your example code already looks pretty good. If you are getting less verbose, you will always loose some information. 

Minimal Version

To demonstrate this, let's take a look at a minimal version of your code:

cmake_minimum_required(VERSION 3.4)
project(AwesomeScheduler)

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/bin")

find_package(Boost REQUIRED COMPONENTS system filesystem)

include_directories(header)

add_executable(Dispatcher src/socket.cpp src/dispatcher.cpp)
add_executable(EndUser src/socket.cpp src/end-user.cpp src/task_properties.cpp)
target_link_libraries(EndUser Boost::system Boost::filesystem)


I have 


moved the source files into the add_executable() calls
eliminated the header files
used the IMPORTED targets from Boost, which implicitly declares the header paths also
done some cosmetic changes to the global settings


used the more cross-platform CMAKE_CXX_STANDARD setting
using .. from the binary dir looks odd, I assumed something relative to the source dir



Something in Between

Because grouping the source files and adding the header files has its advantages in respect of readability, maintainability and CMake's own abilities during build environment generation, here is what I would have done in the setup you have described here:

cmake_minimum_required(VERSION 3.4)
project(AwesomeScheduler)

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/bin")

find_package(Boost REQUIRED COMPONENTS system filesystem)

set(
    SOCKET_SOUCE_FILES
        src/socket.cpp
        header/socket.h
)
set(
    ENDUSER_SOURCE_FILES
        src/end-user.cpp
        header/end-user.h
        src/task_properties.cpp
        header/task_properties.h
        header/util.h
)
set(
    DISPTACHER_SOURCE_FILES
        src/dispatcher.cpp
        header/dispatcher.h
        header/util.h
)

add_library(Socket OBJECT ${SOCKET_SOUCE_FILES})
target_include_directories(Socket PUBLIC header)

add_executable(Dispatcher ${DISPTACHER_SOURCE_FILES} $&lt;TARGET_OBJECTS:Socket&gt;)
target_include_directories(Dispatcher PRIVATE header)

add_executable(EndUser ${ENDUSER_SOURCE_FILES} $&lt;TARGET_OBJECTS:Socket&gt;)
target_include_directories(Dispatcher PRIVATE header)
target_link_libraries(EndUser Boost::system Boost::filesystem)


Now you have


the possibility to 


add/remove files conditionally to your source file lists
reuse the lists in calls to e.g. set_source_files_properties() or source_group()

the headers getting checked for availability and added to IDE projects during generation
the grouping of Socket sources into a object library with e.g. it's own set of target properties to be modified 
no global include directory anymore, but target specific include directories 


on this small project with only one header folder it might be oversized, but if your code gets larger you should definitely think about the directory structure of your code
So it could look something like

AwesomeScheduler/
  CMakeLists.txt
  Dispatcher/
    CMakeLists.txt
    src/
      dispatcher.cpp
      dispatcher.h
  EndUser/
    CMakeLists.txt
    src/
      end-user.cpp
      end-user.h
  lib/
    Socket/
      CMakeLists.txt
      src/
        socket.cpp
      include/
        socket.h
  include/
    util.h




References


FindBoost CMake Module
https://stackoverflow.com/questions/6594796/how-do-i-make-cmake-output-into-a-bin-dir
https://stackoverflow.com/questions/10851247/how-to-activate-c-11-in-cmake
https://stackoverflow.com/questions/2924037/separate-include-and-src-folders-for-application-level-code
https://stackoverflow.com/questions/2360734/whats-a-good-directory-structure-for-larger-c-projects-using-makefile
https://stackoverflow.com/questions/36872117/various-libs-in-subfolders-how-do-i-export-them-to-the-parent