Abstract The main objective of this study is to clarify the current challenges and preconditions relating to product portfolio management (PPM) and widen the PPM framework over horizontal and vertical portfolios, including a related governance model, strategic performance management and the PPM process. This study analyses comprehensively the current PPM literature and the relevant practices of 10 case companies representing business areas such as hardware (HW), software (SW) and Services. This study approaches PPM from a more comprehensive viewpoint as all product life cycle phases and product structure levels are not covered well in this context by the earlier literature. The principal results of this study involve revealing the need for a new PPM governance model including strategic targets, KPIs and the PPM process according to vertical and horizontal portfolios. The created PPM framework clarifies the strategic role of PPM in cross-functional analysis and decision making for commercial and technical portfolios. The role and the impact of strategic PPM have been further enhanced by positioning the PPM process on the level of other business processes. The created PPM framework enhances the collaboration between business and engineering teams. The managerial implications include the potential preconditions of clarifying the dynamic and active role of PPM at the level of other business processes. The findings can aid business managers in understanding PPM as an entity that has a role in managing the entire product portfolio and its renewal based on strategic performance measures over horizontal and vertical portfolios according to cross-functional governance bodies. This highlights the criticality of managing all items both in commercial and technical portfolios. The role of other business processes should be highly operational by executing product development, marketing and sales, delivery and care activities according to PPM decisions. The primary role of PPM should be active management of the entire product portfolio over product life cycle phases and product structure levels, instead of merely focusing on new product development, to ensure product portfolio renewal. / Tiivistelmä Tämä tutkimus selventää tuoteportfolion hallintaan liittyviä edellytyksiä ja haasteita, sekä laajentaa tuoteportfolion hallintamallia, suorituskyvyn johtamista ja prosessia horisontaalisesti ja vertikaalisesti. Tuoteportfolion hallintaa on lähestytty kattavasti analysoimalla nykyistä kirjallisuutta, sekä kymmenen kohdeyrityksen käytänteitä nykytila-analyysin keinoin. Kohdeyritykset edustavat useita liiketoiminta- ja tuotealueita kattaen laitteiston, ohjelmiston ja palvelut. Tämä tutkimus lähestyy tuoteportfolion hallintaa laajemmalta katsantokannalta kuin nykyinen kirjallisuus joka ei kata kaikkia tuotteen elinkaaren vaiheita ja tuoterakennetasoja. Tämän väitöstutkimuksen tärkeimmät tulokset liittyvät uuden tuoteportfolion hallintamallin tarpeellisuuden esille tuomiseen, sisältäen tuoteportfolion strategiset tavoitteet, suorituskykymittarit ja hallintaprosessin perustuen vertikaalisiin ja horisontaalisiin tuoteportfolioihin. Luotu viitekehys selkeyttää tuoteportfolion hallinnan strategista roolia organisaatiorajat ja liiketoimintaprosessit ylittävässä analyysissa ja päätöksenteossa liittyen kaupallisiin ja teknisiin tuoteportfolioihin. Strategisen tuoteportfolion hallinnan roolia ja merkitystä on erityisesti korostettu nostamalla tuoteportfolion hallintaprosessi muiden liiketoimintaprosessien tasolle. Tässä tutkimuksessa luotu tuoteportfolion hallinnan viitekehys vahvistaa yhteistyötä liiketoiminnanjohto- ja insinööritiimien välillä kaikilla organisaatiotasoilla. Työn kontribuutiot yritysjohdolle korostavat tuoteportfolion hallintaprosessin keskitettyä, dynaamista ja aktiivista roolia johtaa yrityksen kaupallisia ja teknisiä nimikkeitä horisontaalisesti ja vertikaalisesti kokonaisuutena perustuen strategisiin suorituskykymittareihin. Tuoteportfolion hallinta yli horisontaalisten ja vertikaalisten portfolioiden mahdollistaa tuoteportfolion uudistumisen yli kaikkien elinkaarivaiheiden ja tuoterakennetasojen. Muiden liiketoimintaprosessien roolin tulisi olla selkeästi operatiivinen toteuttaen tuotekehitykseen, markkinointiin, myyntiin, tilaamiseen, hankintaan, toimittamiseen ja huoltoon liittyviä tehtäviä perustuen strategisiin tuoteportfolion hallinnan tavoitteisiin ja suorituskykymittareihin.

The main goal of this dissertation thesis is to design and verify a new concept of process management principles, procedures and tools application, utilizable in the software development project management field. Emphasis is placed on creating a general (i.e. generally usable) concept, derived from solid theoretical background and suitable for further expansion and modifications. The theoretical part of the thesis has two main chapters. In the "Process management" chapter, the individual derived principles (Effectiveness, Added value, Coherence, Portability, Adequate standardization, Measurability, Clarity, Integration, Accountability, Continuous improvement) and procedures (Initiation, Identification, Definition, Validation, Implementation, Revision) are described and interconnected into an integrated concept, usable for the introduction and development of process management in the organization, supported by appropriate ICT tools (mainly from four selected areas -- Modeling and Simulation, Performance measurement, Change management, Administration). In the "Project Management" chapter, the project management area is embedded in the broader context of a process-driven organization in line with modern models of strategic ICT governance and ICT services management. The main dimensions of project management as well as the process approach to project management, which helps to bridge the gap between unique/temporary projects and repeatable/stable processes, are described. Basis for the normative project processes design in the following part of the thesis is set by the evaluation of selected models of the project life cycle and project management methodologies. The practical part of this thesis is basically a verification of the concept, described in the theoretical chapters. Firstly, an original project management methodology, suitable for deriving process model of the subject area, is presented. On this basis -- and by using the previously described principles, procedures and process management tools -- the major artifacts of a reference project processes model are elaborated (such as Conceptual model of the subject area, List of events and natural processes, Process pyramid, Process model, Organization model, Indicators pyramid or RACI matrix of roles and processes/indicators /SLAs; setup of selected process model is also verified experimentally by simulations). Critical evaluation of the presented model is an important input for the final assessment of the thesis goals' achievement and proposal of further research fields.